THE SEA-GIRT FORTRESS

"Where are we now?" asked Oswald Detroit, emerging from the cabin of the Diomeda.

"Ask me another," replied his chum, Jack Hamerton, with a merry laugh. "We may be here, we may be there, for all I know. One thing I am certain of: I have just hove the lead, and found that we are in twenty-two fathoms, with a gravelly bottom. That's good enough for me. Also, by dead reckoning, we are three hundred and seventy-eight miles from Lowestoft, and I can't take an observation because of this fog."

"You don't seem at all anxious," remarked Detroit, who regarded the wall of thick white mist with evident mistrust.

"Why should I? The yacht's as sound as anyone could desire, and we've plenty of sea room. Now, if we were anywhere in the neighbourhood of the sandbanks at the mouth of the Elbe, I might feel jumpy. Take the helm, old man; north, eighty east, is the course. I'll get breakfast."

Jack Hamerton was a tall, broad-shouldered fellow of twenty years of age. He might well be described as thick-set, for his head was set upon his square shoulders by a short, thick neck, his arms were brawny, while his legs would have caused many a professional footballer to turn green with envy. His features were inclined towards heaviness, the bushy eyebrows and square jaw denoting force of character amounting to stubbornness.

He was a sub-lieutenant in the Royal Navy, and had lately been "paid off" from H.M.S. Blazer after an arduous commission in the Persian Gulf. Owing to the particular circumstances My Lords had granted Hamerton three months' leave, and the Sub, with an innate love for the salt seas, had chartered an eight-ton yacht, and with Detroit for company had started on a cruise to Kiel.

Oswald Detroit was physically different from Hamerton. He was tall, but slenderly built, yet there was a suppleness in his muscular limbs that had stood him in good stead in the athletic world. His features were clean-cut and regular, his hair of a light-brown hue and inclined to curliness, while his fair skin, in spite of exposure to the wind and sun, contrasted forcibly with Hamerton's almost swarthy complexion.

Detroit was an American by birth—a native of Richmond, Va.—and American in character to his finger tips. He had great faith in his country, and a heap of self-reliance that had carried him through many difficult places. His powers of argument were marvellous, although he invariably hid his most telling points in debate under a thin covering of dry humour.

It was at Lowestoft that the Sub met his future sailing mate for the first time, only a few days before the momentous voyage commenced. Oswald's sister had married a naval lieutenant, a distant cousin of Hamerton's, and thus the two men came in contact with each other.

In a very few hours a bond of friendship was found, for despite their physical difference Hamerton and Detroit had a lot in common. Both were keen sportsmen, and each took a deep interest in yachting, the American being an active member of the exclusive Marblehead Yacht Club. When Hamerton spoke of a cruise to the Baltic, with the crowning attraction of participating in the international racing at Kiel, Detroit's interest was so marked that it wanted little persuasion on the Sub's part to induce the American to accompany him.

Accordingly the eight-ton ketch Diomeda was chartered. Although somewhat small for an extensive voyage across the North Sea, she was far more seaworthy than many a craft of twice or even thrice her tonnage. Hamerton fell in love with her at first sight. It was not on account of her lines, for an almost total lack of sheer, bluff bows, and rounded run aft were not exactly pleasing to the eye. But there was a substantial appearance about the craft that was far more important than artistic curves, while closer acquaintance revealed the fact that she did not belie her appearance.

Barely twenty-eight feet in length, with a generous beam of a third of her over-all dimension, and a draught of nearly six feet, the Diomeda was snugly rigged and canvased. Her cabin-top was low, offering little resistance to the wind, while her cockpit, lead-lined and self-emptying, was essential for passages across the short steep seas betwixt the east coast of England and the opposite shores of the North Sea.

Descending the short flight of steps leading to the cabin, Hamerton discarded his dripping oilskin, and methodically hung it on two hooks in a cupboard devoted to that purpose.

He was in no hurry: he rarely was, save when occasion necessitated, and only then did his activity become apparent. Otherwise he did things in a cool, calculating way that seemed in keeping with his ponderous form.

The cabin was plainly yet comfortably furnished. On either side were sofa bunks, terminating with spacious lockers screened with curtains. Two scuttles in the rise of the cabin-top and a skylight overhead were sufficient to impart plenty of light, but owing to the flying spindrift these were securely fastened. In the centre of the linoleum-covered floor stood a swing table, on which was spread a chart of the North Sea. On the chart lay a pair of parallel rulers and a dividing compass.

The Sub rolled the chart—placing it in a rack so as to be easily got at should it be required—dived into the pantry, and produced a couple of enamel mugs, plates and rather tarnished knives and forks. Then from another division he hauled out a teapot, some bread, butter, and a bundle of rashers.

Taking the latter, he made his way along the steeply inclined floor towards the fo'c'sle.

On the for'ard bulkhead was a clock and a barometer, surrounded by four signal flags representing the yacht's name in code. The hands of the clock pointed to a quarter to five, the barometer, 30.01, steady; both pieces of information Hamerton entered in a rough logbook.

The fo'c'sle was small, and, being battened down, ill-ventilated. The heat from the Primus stove and the odour from the frizzling bacon, combined with the erratic pitching and listing of the yacht, would have upset many an experienced sailor, but unperturbed the amateur cook proceeded with his self-imposed task.

"On deck, there!" shouted Detroit, raising his voice to make himself heard above the roar of the atmospheric stove.

There was something urgent in the tone of the American's voice. Hamerton backed out of the narrow fo'c'sle door, and, without waiting to put on his oilskin, ran up the ladder and gained the cockpit.

The fog was not so dense as it had been ten minutes previously. The rising sun had partially dispelled the white wall of vapour, so that it was possible to see about fifty yards ahead.

"Yes, I hear," replied the Sub. "A steamer of some sort, tearing along at a furious pace. A quarter of a mile off, I should say, but close enough in this mirk."

With that Hamerton snatched up a fog trumpet that lay on the lee seat of the well, and made the welkin echo to three loud blasts—the recognized signal of a sailing vessel with the wind abaft the beam.

No reply came from the unknown vessel. Momentarily the noise of her engines and the swish of water as her bows cleft the waves grew louder and louder.

"Down helm, sharp!" ordered Hamerton. "What in the name of Davy Jones is that idiot carrying on like that for?"

Round swung the Diomeda slowly yet surely, but before the sails began to flap, the disturber of her crew's peace of mind loomed out of the fog.

It was a large destroyer, painted a dull grey. She was travelling at close on thirty knots. Dull red flames were spurting from her four squat funnels. Her decks were being swept from end to end with water, while the spray, dashing against her funnels, trailed off into wisps of steam, leaving the fore side of the smoke-stacks bleached with salt. In spite of the wave-washed decks, men, clad in greenish-grey oilskins, were standing by the two torpedo tubes on deck, while right aft stood a seaman holding a red-and-white flag in his extended hands.

This much the crew of the Diomeda had barely time to take in, for close astern of the leading destroyer came another, and another, and yet another, less than thirty feet separating the black cross ensign of the leading boat from the knife-like bows of the one next astern. Any miscalculations on the part of the coxswains of the several boats would inevitably result in disaster.

Just as the fourth destroyer darted past the violently pitching yacht—for she was in the thick of the combined "wash"—one of her crew, who was in the act of securing a stanchion rail, slipped on the heaving, wave-swept deck. Unnoticed by his comrades, he rolled under the rail and fell into the sea.

The Diomeda was "in irons". Her sails were slatting violently in the wind. She carried no way, nor would she answer to her helm, and some minutes elapsed ere the ketch fell off sufficiently for her canvas to draw.

Running forward and gripping the shrouds, Hamerton seized a boathook. The unfortunate man still floated, face upwards, but made no attempt to save himself.

"Guess he's broken his back," shouted Detroit to his companion, in reply to which the Sub nodded. Falling off a boat travelling at thirty knots, a man would strike the water with terrific force.

Leaning outwards to the full extent of his left arm, the Sub made a futile attempt with the boathook to reach the sailor.

Then to his surprise Hamerton saw the American leap out of the cockpit, steady himself on the waterways for a brief instant, then plunge into the sea.

"Silly ass!" grunted the Sub, although recognizing Detroit's pluck. "I'll have two men to haul aboard now instead of one."

With that he made his way back to the cockpit to steady the yacht on her helm. Then it was that he found that Oswald had acted with discretion as well as bravery, for before leaping he had taken a turn of the end of the mainsheet round his waist. Rescuer and rescued were trailing astern at the end of forty feet of rope.

Hauling the Diomeda's headsails to windward, Hamerton soon had the yacht hove-to, though forging slowly through the water. It was then a comparatively easy task to get the mainsheet in until Detroit and the seaman were alongside. Then waiting till a wave brought the man within arm's length, the Sub clutched hold of him, and with a powerful heave lifted him on deck and into the well.

Without assistance Detroit scrambled up, and assisted his comrade to attend to the rescued seaman.

"He's alive all right," announced Hamerton. "A lump of a fellow, by Jove!" he added, critically regarding the stalwart, fair-haired Teuton. "We'll get those wet clothes off him and carry him below. You will do well to change. Never mind about the boat, she'll take care of herself for a while."

The destroyers were now out of earshot, swallowed up in the still dense watery mist. More than likely the absence of the unfortunate seaman would not be noticed for some considerable time, and then it was doubtful whether the vessels of the flotilla would retrace their course far enough to come in touch with the Diomeda.

"I'm glad I didn't miss that sight, by Jove!" said Hamerton, with unstinted praise. "Those Germans know how to handle their torpedo craft. Fancy taking them at that bat through a fog!"

"All the same, it's part of the game, and only by constant practice can they keep in a state of efficiency. Our fellows are pretty smart at manoeuvring, but these Germans appear to run all sorts of needless risk, and still manage without serious accidents. Finished changing? Good! You might get on deck and see how things are progressing."

Barely had Detroit resumed his post at the helm when out of the fog came a succession of dull flashes, punctuated by the deafening detonation of a number of quick-firing guns. Then, like a veil rent in twain, the fog partly lifted, revealing a large battleship, cleared for action, and blazing away with her light armament in the direction of the small British yacht.

CHAPTER II

Through the Fog

"Yes, one of the 'Deutschland' class," added Hamerton, who at the first report had followed his companion on deck. He recognized the battleship by her three telescopic funnels as belonging to a type immediately preceding the first of the Kaiser's Dreadnoughts. Although her principal armament consisted of only four eleven-inch and fourteen six-inch guns, she was not an antagonist to be despised.

"She's engaged in manoeuvres," continued the Sub. "Those destroyers we saw are evidently about to attack her, and in the fog she mistook us for one of them."

"Rather. I know what it is to be on the qui vive. Officers and men are bound to get jumpy, and a dinghy might easily be mistaken for a torpedo boat. Remember the case of the Russian Baltic Fleet and our trawlers in the North Sea some years ago. But now's our chance to get rid of the poor fellow we picked up. Hand me the Code Flag and letter H."

Deftly Hamerton toggled the flags, signifying "Important; I wish to communicate", to the halyards, and hoisted them to the peak.

The German battleship was now less than four hundred yards to leeward and moving slowly through the water. At any moment she might be swallowed up in the fog, which showed signs of increasing in density.

"There's the reply," exclaimed Detroit, as two flags fluttered from the after-mast of the battleship.

"'I F,'" announced the Sub, placing his binoculars on the seat and seizing the codebook. "The rotters! They decline to hold any communication. There, she's off! Steady on the helm, old man! It's time I saw to those rashers."

Once more Hamerton entered the cabin. The rescued man was still lying on the floor, staring vacantly at the skylight.

"Are you better?" asked the Sub in as good German as he could muster. His command of foreign languages, like that of the majority of British officers, was poor. His German in particular was execrable.

"Ja," answered the man, without removing his gaze from the skylight. The reply was purely mechanical, for Hamerton could see that the fellow was not in full possession of his faculties.

"He'll recover all in good time," soliloquized Hamerton as he made his way to the fo'c'sle. "A glass of brandy and water will do wonders. Hallo! What's this?"

For the young officer had made the disconcerting discovery that in the "wash" of the destroyers the frying-pan had jumped off the stove, and four rashers lay stuck to the fo'c'sle floor in their own fat, whilst rivulets of dried grease had traced fancy patterns on the sides of the lockers and over a bundle of spare sails. To complete the disorder, a can of paraffin and a tin full of soda had come into violent contact, with the result that the contents of both gave additional flavour to the stranded rashers. But for this, Hamerton might have replaced the bacon in the frying-pan, reflecting that much of the pleasure of yachting consists in tolerating discomforts. He drew the line at rashers à la soda and paraffin.

"You'll have to whistle for hot grub, Detroit," he called out. "There's a most unholy mess for'ard. Hot coca and biscuits are the best I can do."

Detroit's reply was to give a tremendous salute upon the foghorn, an action that brought the Sub on deck.

"Destroyers are coming back," announced the American, "and the fog is as thick as ever it has been. We've tumbled into a regular hornet's nest of torpedo craft."

Five minutes later the sharp rattle of quick-firers announced that the battleship had been attacked by the destroyers, a form of practice that is regularly gone through by the Kaiser's ships. Then all was quiet.

Two more hours sped. The Diomeda still maintained her course, slipping through the fog-enshrouded water at a bare four knots.

The German sailor, having been given a "stiff peg", was able to sit up. Beyond feeling stiff and bruised by reason of his fall, he was little the worse for his immersion, and, upon being questioned, gave his replies in an intelligent and straightforward manner.

His name, he said, was Hans Pfeil. His rank corresponded to that of Chief Yeoman of Signals in the British navy. His ship was S167, one of, the most powerful of the Elbing-built destroyers, and belonging to the Second Division of the Borkum flotilla. The boats had left Borkum at midnight to deliver an attack upon the battleship Hannover.

"What was the approximate position of the division when you fell overboard?" asked Hamerton.

"We're out in our dead reckoning, Detroit," said he. "I thought we'd left the lightship well on our starboard quarter. If this man's story is correct—and I have no reason to believe otherwise—we ought to be within hearing distance of the lightship. This fog is the most persistent I have ever experienced."

"We will soon be in the way of steamship traffic in and out of the Elbe and Weser."

"Or else piled up on one of those treacherous sandbanks. I'll see what the North Sea Pilot says. Ah! Here we are: 'Borkum Riff, or Flat; syren in fog, one blast of five seconds every minute'. That's what we have to listen for, old man."

Returning to the cabin, Hamerton resumed his conversation with Hans. The seaman was profuse in his expressions of gratitude, for he realized that but for Detroit's plucky act he would be lying in the bed of the North Sea, twenty fathoms deep, instead of finding himself in the cabin of the Diomeda. He knew Kiel well, for not only had he been stationed there, but before he was called up for sea-service in the imperial navy he had been a fisherman at Flensburg, a town in the province of Schleswig. Thus he was able to give his benefactor much valuable information concerning the yacht anchorage in the neighbourhood of Kiel Bay.

The man was evidently troubled. His sense of duty, fostered by the cast-iron discipline of the German navy, prompted him to report himself as soon as practicable, and Hamerton, nowise loath to recognize a praiseworthy trait in Hans Pfeil's character, promised to tranship him to the first steamship bound either for Hamburg or Bremen.

"You're right," assented the Sub, after listening till the lightship again gave its warning note; "but goodness only knows the direction whence the sound comes. Seems as if it's on our port bow."

"The fog's not only trying to the sight, but to the sense of hearing as well. We'll carry on, and trust to luck. It's my trick at the helm now, my boy."

For another hour the Diomeda hung on her course. The syren of the lightship sounded louder and louder, while the hooters of several vessels, adding to the din, betokened the fact that the yacht was crossing one of the great steamship routes.

Then, with the same sort of suddenness that characterized the previous temporary dispersal, the fog cleared, revealing a large red vessel with three masts. On her fore- and mizen-masts were black globes, with a pyramid-shaped cage on the main, while any doubts as to her identity were set at rest by the words "Borkum Riff" on the side showing towards the yacht.

Several of the lightship's crew gazed stolidly at the unfamiliar rig of the Diomeda, and, in response to a wave of Hamerton's arm, gravely raised their caps.

Hamerton missed an opportunity. He could have signalled or hailed the lightship with the news that he had rescued a sailor from a German destroyer, The intelligence would then have been sent by wireless to the mainland. But he did not, and subsequent events brought home to him the error he had made in omitting to do so.

"All plain sailing now," he remarked. "Keep as we are; we'll soon pick up the Norderney Gat lightship, and then the Elbe. I'm jolly glad we made Borkum Flat light-vessel, for, as I said before, I've no wish to find myself amidst the sandbanks to leeward."

"The Germans are fortifying Borkum very heavily, I believe," said Detroit. "In fact, they are turning the whole of the Frisian Islands that belong to them into fortresses. Guess they'll take the rest of the islands as well before long. John Bull is asleep, I guess, or he would demand an explanation."

"John Bull sleeps with one eye open, old man. Take my word for it. Besides, the Germans are at perfect liberty to defend their coasts."

"Admitted; but it is not a question of defence. These naval bases are also for offence, and, what is more, they exist solely for a torpedo raid on British ports when 'The Day', as they call it, comes. There can only be one predominant race in the world, and that ought to be the Anglo-Saxon."

"Guess you've hit it, Hamerton. Imagine an offensive and defensive alliance between Great Britain and the United States! Nothing could stand against it. Other European and Asiatic countries, realizing the impossibility of continuing in the race for world supremacy, would climb down. Reduction of armaments would follow automatically, and we should be entering into a state that the most ardent delegate to the Conference at The Hague never dreamt of."

"And if they did they would soon patch matters up, like two children. Our old axiom, 'Blood is thicker than water', still holds good, and will do so till the end of time. That's why it licks me to understand why Great Britain contracted that alliance with Japan."

"My dear Detroit," exclaimed the Sub deprecatingly, "you must allow that the powers that be are better able to decide these matters than you or I. For my part, as an officer of the Royal Navy, I must take things as they are, unquestioning and loyally."

"See what a rotten mess of things has resulted," continued Detroit. "You may not admit it, but I reckon in your innermost mind you do. Here's the U.S.A. on the verge of a quarrel with Japan over the yellow immigration question. Great Britain is forced to increase her naval expenditure out of all proportion to the rest of the proceeds of taxation, in order to maintain a superiority over Germany's rapidly growing navy. Your Two-Power Standard was knocked on the head years ago. Yet, because of a sort of sentimental yearning on the part of your diplomatists towards Japan, there is a peril of a disagreement between the two great Anglo-Saxon races, whereas they should be shoulder to shoulder."

"Then where does France come in?" asked the Sub, unconsciously warming to the discussion. "We have an understanding with her."

"With all due respect to your Gallic neighbours, friend, France will have all her work cut out to attend to Austria and Italy, who will assuredly side with Germany."

"Ah! There you have a totally different case. Russia, after the ordeal of her disastrous struggle with Japan, is gradually but surely regaining her position as a naval and military power. In the near future she hopes to see a solid, compact Slav Empire extending from the Arctic Ocean to Cape Matapan. Then, profiting by her experiences, she will again meet Japan but not until the Anglo-Japanese alliance is dissolved. Once these aims are realized, Russia will stand aloof in all European disputes until the Triple Alliance is weakened either by victory or defeat. Since the barren Steppes of Siberia cannot support her surplus population, she must find another outlet, and that will be west-wards, as soon as she is strong enough to measure weapons successfully with Germany, for the Slavs and the Teutons never will hit it off together."

"Plenty of opportunity to consider the situation when the time comes," said Hamerton, with true British indifference. "Meanwhile, here we are in the North Sea, with a thick fog hanging about, and a lee shore not many miles away. This situation is more important to me than the whole of the international complications put together."

CHAPTER III

A Loss and a Find

Late in the afternoon, the wind falling light, Norderney lightship was passed. Curiously enough, with the breeze dropping the fog dispersed, and Hamerton was able to set a course for the Elbe light-vessel.

"Here's a tramp bearing down upon us," he announced, after intently watching the oncoming craft through his binoculars. "We'll signal her." Again the flags that the German warship had all but ignored were hoisted, and before long the crew of the Diomeda saw the steamship alter helm and head so as to pass within a cable's length of the yacht.

She flew no ensign, neither did she reply by signal to Hamerton's request to communicate.

"I'll semaphore her," announced the Sub, producing two red-and-yellow hand flags from a locker. For nearly two minutes he vainly attempted to enter into conversation.

"The bounders don't understand," he growled. "She's not a British vessel, I'll bet my bottom dollar on it. We'll hoist the ensign, and hail them through the speaking trumpet."

Out fluttered the red ensign. Still there was no reply that gave a clue to the tramp's nationality. But she was now within hailing distance.

"She's either a Dutchman or a German," said Detroit. "The name on her bows conveys nothing. Why not hail them in German?"

"Couldn't trust myself to make a public confession of my inability," replied Hamerton, with a laugh. "But, by Jove, although we're doing all this for Pfeil, I quite forgot him. He can do the chin-wagging part of the business."

In answer to a shout from the Sub, Hans Pfeil, who had been asleep in the fo'c'sle cot, came on deck. His clothes were still wet, since the air was too moist for drying purposes, and a comical figure he cut, wrapped up in a blanket, with his oilskin coat flung round his shoulders.

The sailor hailed, and an animated conversation took place between him and the skipper of the tramp.

"Heave her to," ordered Hamerton, seeing that the German tramp's propeller was going astern, and that the vessel was losing way. "They're going to lower a boat."

The two craft were now less than a cable's length apart and hardly moving through the water, but Hamerton would not risk running the Diomeda alongside the wallowing hull of the tramp. He waited for a boat to be sent.

Meantime Pfeil went below to assemble his saturated garments. Then, clad only in his oilskin, and with the bundle of clothing under his arm, he took leave of his rescuers, again thanking them for saving his life.

This done, he entered the waiting boat, and was taken to the tramp. Without further delay the steamship gathered way, hoisting and dipping her ensign, to which the Diomeda replied, while from the taffrail could be discerned the oilskin-clad figure of the German sailor, still waving adieux to the men who had saved him from a watery grave.

"Haul down that ensign, old man," said the Sub when the tramp was almost out of sight. "It's too pretty to be flapping itself against the mizen halyards, now that a breeze is springing up."

Detroit, with his usual energy, sprang out of the cockpit and lowered the bunting, rolled it in a professional manner and jammed it between his knees, while he secured the halyard to a cleat. While thus engaged one end of the halyard slipped from between his fingers, and streamed to leeward. Hurriedly grasping the mizen shroud with one hand, he leant outboard to recover the errant cord. As he did so the sudden movement dislodged the ensign, and in an instant it was overboard.

"Can't be helped," was the reply. "Accidents will happen, you know. We can get another for a matter of five or six marks at the first chandler's shop we come to ashore. But I rather fancied myself dropping anchor off the custom house at Cuxhaven with the red ensign at the masthead to signify that we had sailed a little eight-tonner from England."

"I'm an awkward mule," ejaculated Detroit. "Hope you are not superstitious; losing an ensign looks like a bad omen."

"Thanks, I'm not in the least superstitious," was the reply. "After all, it's of little consequence. But it's high time I went below and filled and trimmed the lamps."

The Diomeda's lamp-room was a small cupboard in the fo'c'sle. To get to it Hamerton had to remove the topsail that had reposed on the fo'c'sle floor since the previous night. As he did so he noticed a book lying under one of the folds of the canvas.

It was a small, blue-covered volume, saturated with salt water. A glance at the title told him the nature of the work. It was a treatise on the Schwartz-Kopff twenty-five-inch torpedo, a highly confidential work of which the British Admiralty had failed to obtain a copy in spite of the most strenuous efforts on the part of the Naval Intelligence Department.

"By Jove, this is a find!" ejaculated the Sub gleefully. "It must have fallen out of Pfeil's jumper when we slipped off his wet clothing. But I must stow it away very carefully, for there'll be considerable trouble if the German custom-house authorities chance to lay their hands on it when they start rummaging in search of contraband. Let me think, now; where's the best place?"

It was certainly curious that, though the Sub had often mislaid articles on board, and only after a laborious search had he been able to find them (for below decks the yacht was a labyrinth of lockers and odd corners), now, because he wanted to conceal a small book, he was at a loss to find a suitable hiding place.

"Capital idea!" he exclaimed, slapping his thigh, and at the same time giving his head a tremendous blow against an obtrusive deck beam. "I'll stow it in the false bottom of the stove. It will stand a good chance to dry, and at the same time ought to be quite safe from detection."

As soon as the "manual" was hidden, Hamerton proceeded with his task of getting the lamps ready for their night's work.

"It's piping up," announced Detroit, as a vicious puff struck the yacht's sails, causing her to heel till her lee planks were awash.

"Yes, the glass is falling rapidly," said the Sub. "We're in for a dirty night."

"No, not with a dangerous lee shore. If I knew the coast it would be a different matter. We'll heave to on the port tack as soon as it gets dark. Meanwhile we'll stow the mizen and change the jibs. Easy canvas is best for a job of this sort."

With the rising wind came the rain, hissing upon cabin top and obliterating everything beyond a few yards. Snugly clad in oilskins, the two men remained on deck, for although the helm was lashed and the yacht hardly making half a mile an hour to windward, neither cared to go below and turn in.

Hour after hour passed without any attempt at conversation. Occasionally Detroit would make some remark about the state of the weather, to which Hamerton would reply with a grunt that could be taken as expressing assent or otherwise.

Fortunately the rain served a good purpose. It kept down the sea, so that, instead of vicious, crested waves breaking inboard, there was little more than a long, sullen roll.

"Lights ahead!" announced Detroit, as a faint luminosity became visible in the rain-charged darkness.

"Yes, searchlights. They always look like that in rainy weather. We're apparently in the thick of the German naval manoeuvres. It may be Heligoland. They say the place bristles with powerful searchlights."

"Heligoland, eh? I'd just like to have a look at that place," exclaimed the American. "Many years ago my father spent a holiday there. That was when it was a British possession, used principally as a bathing resort for German visitors. He lived in Germany for some time when he was about my age."

"I'm afraid you won't be able to gratify your wish, old man," said the Sub. "It's forbidden ground now. In 1913 it was strongly fortified, and shortly after that the island was given over solely to military and naval purposes. The civil population had to clear out. It's a sort of second Kronstadt. Our Intelligence Department would dearly like to know a great deal more about it than they do at present."

"Don't you think the British Government was a bit of a fool to give the place away?"

"No, certainly not. We did jolly well out of the deal. Had a vast tract of territory in Africa in exchange for a little lump of sandstone that looked very much like falling into the sea."

"That's the average Britisher's notion—that is, if he thinks about it at all. The German view is very different. As colonists the Teutons do not shine, except, curiously enough, when under any Government but their own. Very well. They give you a slice of virgin territory. You develop it, and it increases in value a thousandfold in a couple of decades. When 'The Day' comes, should Great Britain be overwhelmed by the Triple Alliance, Germany takes back her former territory—and a lot besides—all ready for her much-wanted place in the sun."

"You're a jolly old croaker, Detroit," exclaimed the Sub. "I'll bet my last halfpenny that the British navy will be top dog for a good many years to come. I don't fancy that you and I will see the Teutons walking through London with fixed bayonets, and the Kaiser dictating terms of peace in Buckingham Palace. Hallo! The searchlights are out. Evolutions finished for the night. What's the time, I wonder?"

Thrusting back the sliding hatch, Hamerton looked at the clock on the fore bulkhead of the cabin. It was just 2 a.m.

As he reclosed the hatch his foot slipped on the wet grating, and his rubber-soled boot came in contact with a hard substance close to where the yacht binnacle stood.

"Good job I didn't sit on the compass, by Jove!" ejaculated the Sub. "But what's this? What idiot placed it there?"

For the object he had kicked was a large belaying pin that unaccountably had been propped up against the binnacle.

"The mischief is done, at all events," continued Hamerton. "The attraction of that lump of iron has affected the compass. We may be points out of our course. Just watch."

Bringing the belaying pin back to its former position, Hamerton carefully observed its effect upon the sensitive needle of the liquid compass.

"And goodness only knows how long it has been like that. Perhaps before the yacht was hove-to perhaps even when we passed Norderney Gat."

"Well, we've a good offing, so there's little harm done. The wind is falling some, and if only this tarnation rain would quit——"

"Nothing, I guess," replied Detroit, after a few moments. "What's the matter with your nerves?"

"There's nothing the matter with my nerves," asserted the Sub with asperity. "Feel my pulse. But I could swear I heard a fellow calling out, 'Who goes there?' in German."

"Guess I'll have to take your word for it," he said. "I'll git. It's time I made some coffee."

The Sub watched his companion descend into the cosy cabin and strip off his glistening oilskins. Then, to avoid the glare, he closed the sliding hatch, and peered steadfastly into the mirky night.

The rain was coming down with torrential violence. The wind had died utterly away, and the saturated sails were slatting violently from side to side with the motion of the craft.

Beyond the patter of the heavy raindrops, no sound came from the black vault that encompassed the Diomeda on every side.

"If only I could pick up a light!" he muttered; then, mainly with the idea of doing something, he picked up the coiled lead-line.

"Five fathoms, by Jupiter!" he exclaimed; then, seized by an inspiration, he dived into the cabin and bent over the chart. According to the course the minimum depth ought to be thirteen.

"We've muddled the whole show, Oswald," he announced. "We're inside the five-fathom line, and that means we are only a few miles from shore. I'll put her due west, and see what comes of that. There's enough wind now to give her steerage way."

"Couldn't do better," replied Detroit laconically, "unless it's to have some coffee and a few rusks. I'll be slick about it."

Hamerton returned to his rain-exposed post, put the little craft's head in the desired position, and waited. Five minutes later he made another sounding. This time it was four and a half fathoms.

"I'll carry on," he resolved. "It may be a slight irregularity in the ground, although the general tendency is for it to deepen."

"Say, ready for your coffee?" asked Detroit, holding a cup in his extended hand through the partially open hatchway.

"Far from it," replied the Sub. "Come on deck and give a hand to put her about. The water's shoaling rapidly."

"Nor'-nor'-west. I'll keep her at due south for a bit until we find deeper water."

Slowly the Diomeda came into the wind and paid off on the other tack. As she did so Hamerton noticed that, in spite of the heavy rain, the seas were steeper, and showed a decided tendency to break.

"Guess that's surf," said the American, as the dull rumble of a heavy ground swell was heard above the hiss of the rain. "Dead ahead, too."

Hamerton heard it also. The Diomeda was making straight towards a sandbank. Unhesitatingly he put the helm hard up. He would not risk going about; he chose the lesser danger of gybing all standing.

With a thud the boom swung over, and the stanch little craft drew away from the hidden danger. Her course was now nor'-west.

"Still shallow," announced the Sub. "It's less than four fathoms, but the water seems calmer."

"Light ahead!" shouted Detroit. "Showing red and white. We're right on the dividing line between the two sectors."

"I see it now," replied Hamerton, as he altered his helm to bring the Diomeda more into the arc of the white light. "Hanged if I know what or where it is, but, by Jove, there's a crowd of lights beyond!"

Through the rain a multitude of yellowish lamps blinked after the manner of a street, except that, instead of two rows, there were four or five. The water, too, was almost calm, ruffled by a faint breeze that contrasted vividly with the strong wind but a few hundred yards astern.

The Sub's ready wit grasped the situation. Unknowingly the yacht had entered an anchorage, for the lights represented the anchor lamps of a number of vessels.

"This is good enough for us," he exclaimed. "We'll bring up here till daylight. I shouldn't wonder if we're off the mouth of the Jade or the Weser. Stand by and let go, old man. I'll bring her up into the wind."

Two minutes later the rattling of the chain cable announced the fact that Detroit had let go the anchor. The saturated sails were quickly lowered and stowed, the navigation lights removed, and an anchor lamp hung from the fore stay.

A final look round satisfied Hamerton that he had done all that was humanly possible. The Diomeda was riding snugly in a safe but unknown anchorage.

"Watch below, all hands!" he exclaimed cheerily. "We'll sleep like logs. To-morrow, my dear Detroit, we'll wake up and find ourselves close to a picturesque little German village, and you can go ashore and buy fresh milk and new rolls. Think of that, and dream on it, old man."

Detroit merely nodded. He was already half-asleep. Before the Sub was ready to turn in, his companion was breathing heavily. Five minutes later the crew of the Diomeda were fast asleep, heedless of the peril that overshadowed them.

CHAPTER IV

Arrested

The bump of some heavy object against the yacht's side caused both sleepers to wake simultaneously. It was day; a dull light filtered through the skylight, though not strong enough to be caused by the sun. The Diomeda was rocking sluggishly in the slight swell as she rode to her cable.

"Eight o'clock, by Jove!" exclaimed Hamerton drowsily; "and drizzling with rain, I fancy. What was that noise?"

"We won't find out by lying here," said Detroit, setting the example by springing out of his cot. As he did so came the unmistakable sound of a boathook engaging the little craft's rigging screws, and a peremptory voice hailed in German.

"Custom-house people. They're early," announced the Sub. "It won't do to keep those gentlemen waiting, so I will interview them in my pyjamas."

Pulling back the sliding hatch, and pushing open the half-doors, Hamerton went on deck. Lying alongside was a grey cutter manned by seamen whose cap ribbons and blue-and-white jerseys, showing between the V-shaped opening of their jumpers, betokened them to be man-o'-warsmen of the Kaiser's navy. In the stern sheets sat two fair-haired officers—their chief characteristics fiercely upturned moustaches.

"What ship is that?" asked the elder of the two officers, whose gold-lace distinction marks showed that he was a lieutenant-commander.

"Said I not so, Heinrich?" said the senior officer to his companion in a tone of triumph. "Ach! Why have you not your ensign hoisted on the mainmast-head? Why, indeed, are you flying no ensign at all? Do you know this is a forbidden anchorage?"

To reply to this battery of questions, rapped out with a harsh guttural voice, was a matter of difficulty to Hamerton, whose acquaintance with the German language was somewhat limited. Accordingly he solved the difficulty by answering the last.

"I did not know this is a forbidden anchorage, Herr Lieutenant. That being so, I will change into more suitable attire, and shift my berth as soon as possible."

"What does he want, Jack?" asked the American, who had just appeared from the cabin.

"We've got to clear out. By Jove, we've tumbled into the anchorage off Heligoland!"

For a glance towards the lofty red sandstone rock, fringed with a belt of dazzling white sand and capped by the brilliant hue of the grass, recalled to the Sub the old Frisian rhyme—

"Why not?" asked Hamerton coolly. "It is none too warm or pleasant standing out here in——"

And not knowing the German for "pyjamas", he pointed meaningly at the thin pink-and-white garment he wore.

"By order. You must not go below," replied the officer. "You will enter this boat, to be taken to be interviewed by the commandant of the fortress."

"We can explain everything," said Hamerton. "We'll come out with you directly we get our clothes."

With that the Sub turned his back on the representatives of the Imperial German Navy, and made a step towards the companion hatchway, with a view to making himself more presentable and better attired for the depressing atmospheric conditions.

This laudable intention was nipped in the bud by a couple of bluejackets jumping out of their boat and agilely scrambling upon the Diomeda's cabin top.

For an instant Jack Hamerton's eyes glinted ominously. He was within an ace of knocking the intruders overboard but, recalling that such an act might be disastrous to his comrade and himself, he controlled his feelings with a strong effort.

"It's no use resisting, old man," said he to Detroit, who was beginning to follow the drift of things. "They have put us under arrest for contravening some silly regulation. We've got to go ashore in their boat. Hang it! How can a fellow stand on his dignity when he's rigged out in pink-and-white pyjamas?"

"Enter the boat instantly," ordered the German officer. "Your clothes will be handed to you."

The two members of the Diomeda's crew stepped into the boat. One of the officers boarded the yacht, and, accompanied by a seaman, entered the cabin. Presently the latter reappeared bearing an assortment of clothing.

"And mine too!" added the Sub, after a hasty examination. "And my pocketbook and cigarette case! Here, this won't do!"

"Stop!" said Hamerton. "Before we go we want our purses and other personal property that have been taken from our pockets."

"It is unnecessary," was the reply. "There will be no need for you to have money ashore."

The oars dipped and the boat glided towards a stone pier, leaving the junior officer and two men in possession of the Diomeda.

Hamerton made good use of his eyes during the passage. By a pure fluke the Diomeda had entered the newly completed artificial harbour, and was anchored within fifty yards of the nearest of a triple line of grey torpedo-boat destroyers. Beyond them, and closer inshore, were more than twenty of the latest type of German submarines, vessels of slightly over twelve hundred tons, and capable of action within a radius of seven hundred miles. One peculiarity he especially noticed: in addition to the twin periscopes there were four slender cylinders of almost the same height, although inclined at various angles with the deck.

So keen was his interest that the German officer leant forward and tapped him on the shoulder.

"All right, my attentive fire-eater," mused the Sub. "You've caught me napping. I ought not to have let you see that I was curious. All the same, I think I know what those tubes are for. If they are not pneumatic guns for discharging aerial torpedoes from a submerged submarine, I'll eat my hat."

Nevertheless Hamerton ignored the lieutenant's order, although he concealed to some extent the fact that he was making extraordinarily good use of his powers of observation.

The face of the cliff was bristling with heavy ordnance, some of the guns being at least equal to the heaviest weapons mounted on the Royal Sovereign and her sisters—the latest completed battleships of the British Navy. As the boat drew nearer, the Sub could distinguish numbers of quick-firers mounted on the edge of the precipitous sides of the island, with searchlights on covered stands a short distance in the rear of the guns; while to prevent the possibility of unauthorized persons landing and scaling the cliffs, a formidable barbed-wire fence, projecting at an acute angle, rendered any attempt in that direction a total failure.

All the while Hamerton and his American friend were scrambling into their clothes, and by the time the boat ran alongside a sheltered stone jetty they found themselves "rigged out" in a medley of garments. Detroit was accommodated with one of his comrade's flannel shirts, since the German officer had not exercised any discrimination in the hurried selection of the garments. Hamerton, unable to button a waistcoat over his broad chest—for the two waistcoats provided both belonged to Detroit—gave up the attempt, and devoted his attention to his footgear. This was made up of two old tennis shoes that the Sub used for rough work on board, and one sock that had the day before been utilized as a "swab" for mopping up a capsized paraffin lamp.

"Say, this is hardly the rig for Coney Island!" exclaimed Detroit. "Guess we look like a pair of hoboes."

"I'll kick up a fuss about this, by Jove!" ejaculated the Sub furiously. "Directly I——"

"Silence!" interrupted the German lieutenant, mistaking Hamerton's attitude for a display of "bluff" on the part of a spy caught redhanded. "It is forbidden!"

"Everything seems to be forbidden as far as you are concerned, my friend," replied Hamerton. "You are certainly labouring under a delusion. I was——"

He pointed to a flight of granite steps alongside of which the boat was being held by the bowman and the coxwain.

At the head of the steps stood a marine, dressed in a blue tunic, white trousers, and a brightly-polished brass helmet. The man brought his rifle smartly to the salute as the German officer passed, then, shouldering his piece, paced the quay in the stolid manner so typical of the Kaiser's soldiery.

Thirty or forty yards away stood another sentry; farther on there were more. The whole place seemed crowded with marines on duty, while every person that Hamerton could see wore either a military or a naval uniform. The civilian element was totally lacking.

The Sub had very little time to make the observation, for from the shelter of a stone building that served as a guardroom a file of marines appeared. With fixed bayonets they fell in on either side of the two members of the Diomeda's crew.

"I imagined so long ago," replied Hamerton. "No matter, they can't bring a case against us. They've no proof. We'll be out of this mess within the next few hours."

Even as he spoke he remembered the confidential book hidden in the stove on board the yacht. If the officials should chance to discover that incriminating article! The thought struck the Sub in a very unpleasant manner, but the next instant his confidence returned. After all, he could explain, and the seaman Pfeil would, he felt sure, corroborate his statement.

"Now, what's going to happen?" asked Detroit, as the pair found themselves alone in a small, whitewashed room, with a heavily barred window several feet above their heads, and a securely locked door between them and the open air.

"Only another exhibition of German high-handedness," replied the Sub. "We'll spring a mine on them. They'll be rather surprised when they learn that you are the son of a United States official in high quarters, and that I am a British naval officer. We'll hold our tongues till we are face to face with the commandant: then, by Jove, we'll enjoy ourselves."

"Guess I wish I had decent things on," remarked Detroit, ruefully surveying his disreputable attire. "Say what you like, Jack, gold lace does not make a man, but a fellow can't stand on his dignity like this."

"I'll have a jolly good shot at it, anyhow," retorted the Sub. "Now, stand by, there's someone coming."

Outside, along the stone corridor, came the sound of spurs jingling on the pavement. Then the door was thrown open, and the lieutenant who had effected the arrest entered, accompanied by a major of infantry.

"You are British?" began the latter in tolerably fluent English. "What is your name, your station, your address of residence?"

"Before we go into these details, Herr Major," said Hamerton, "we should like to know why we are brought here?"

"That is to be told some time after," replied the military officer. "Tell me your names."

"Not at present," said the Sub sturdily. "We'll explain everything to the commandant. We request that we be taken to him with the least possible delay."

"Gott in Himmel!" ejaculated the major. "Do you know who I am?" and twisting his heavy, upturned moustache, their captor tried to impress the two prisoners with the fear of Teutonic officialdom.

"Cannot say I've met you before, Major," replied Hamerton carelessly. "Perhaps my memory is slightly at fault?"

It was on the tip of the Sub's tongue to express his ignorance of the major's identity, but reflecting that perhaps, after all, it would be well to exercise discretion, he replied:

"You will have good cause to do so," retorted the German grimly. "Now, your name?"

"Very good, if you can," remarked the Major, as he prepared to take his departure. "I will, nevertheless, tell you. You will be charged with espionage. You will be lucky if you get less than three years in a fortress, for we Germans have been plagued enough with foreign spies—especially English."

CHAPTER V

A Discovery

Sub-Lieutenant Jack Hamerton was fairly well-informed as far as British naval officers go, and his information regarding the island fortress of Heligoland was fairly extensive, but he still had a lot to learn.

He knew the history of the island from its capture by the British from the Danes in the first decade of the nineteenth century. For nearly ninety years Heligoland existed as a British possession, its safety entrusted to a handful of coastguards, its ordering to a British governor, and its spiritual welfare to a Lutheran pastor. Up till 1850 the then pastor used regularly to offer up a prayer in the presence of his flock that a storm might arise to cast a valuable wreck upon the cliff-bound coast, for the Frisian inhabitants of Heligoland were to a great extent dependent upon the unlawful harvest of the sea.

As for the governor, his office was little more than a sinecure, once the regulations forbidding gaming were enforced. It was said that one of these officials was responsible for the introduction of rabbits upon Sandy Island, in order that his guests might while away the otherwise tedious hours by indulging in a little shooting. To-day, where the twelve-bores of the sportsmen used to bowl over harmless rabbits, enormous Krupp guns, on disappearing mountings, are cunningly concealed in strongly protected pits, for Sandy Island—now known as Sandinsel—has been artificially increased until it is nearly twice as large in extent as Heligoland itself.

Even Heligoland has undergone a complete metamorphosis. The little red sandstone rock, barely three-quarters of a mile in length and a quarter of a mile in breadth, had long been threatened with destruction by the action of the sea. Neglected under British rule, the island seemed fated to be wiped off the map, for after every heavy storm huge masses of sandstone would slide into the raging waters.

But directly Heligoland became a German possession prompt steps were taken to prevent further inroads of the ocean. The worthless rock was destined to be one of the most powerful fortresses in the North Sea, and a perpetual thorn in Britannia's side. Accordingly a massive sea wall of granite was built to encircle the island and baulk the billows of the German Ocean. This done, the work of fortifying the island with modern weapons was begun, and had been rapidly yet secretly carried out.

The British Government was cognizant of the fact that Krupp guns had been mounted, presumably equivalent to the nine-inch weapons. But it did not know that the ordnance consisted chiefly of fifteen-inch guns, conveyed under the most elaborate conditions of secrecy to the island.

His Majesty's Intelligence Department knew of an ammunition tunnel piercing the island from north to west; it knew nothing of the presence of vast artificial caves filled with oil fuel, with discharging pipes capable of supplying a fleet of the largest battleships with crude petroleum in the minimum of time.

The British Admiralty official charts and sailing directions gave the depth of the anchorage in North Haven at less than four and a quarter fathoms anywhere south of a line drawn due east of Nathurn, the northernmost extremity of Heligoland. By the same authority the maximum depth in South Haven, and within a mile of the Unterland, was given as three and three-quarter fathoms. In reality, thanks to strenuous dredging operations between the two islands, a fleet of the deepest-draughted battleships could lie at anchor, protected from all winds by the enormous harbour works that had sprung into existence during the last fifteen or twenty years.

The natural features of Sandinsel Island were favourable for this work, for stretching in a north-westerly direction for almost three miles were a number of rocky ledges, many of their points drying at low tide. Already the Olde Hoven Brunnen and the Krid Brunnen were converted into firm ground faced with granite or ferro-concrete walls, while the work of reclaiming the Witt Klif Brunnen was actively progressing. Although Sandinsel had already outgrown its companion isle in point of size, reclamation works were in a state of activity at Heligoland itself. Wharves extending nearly a mile from Sathurn—the southernmost limit of the original rock—formed an efficient breakwater to South Haven; and the area thus enclosed had been adapted for the purpose of berthing twenty submarines and eighty first-class torpedo boats and destroyers attached to the Heligoland command.

The submarines were the latest creations of the renowned Krupp Germania yard—large, speedy, and capable of operating within a thousand miles of their base without having to be dependent upon fresh supplies of gasoline. Submerged, they could travel a distance that would bring them within striking range of any port on the east coast of Great Britain. They were armed, in addition to the four torpedo tubes, with two fourteen-pounders on disappearing mountings, and, as Hamerton had discovered, with high-angle pneumatic guns, so as to be able, even when submerged, to attack aircraft with a great possibility of success.

Undoubtedly the new Heligoland was a strong fortress for defence. It was more: it was a base for offence, for why were ocean-going destroyers and submarines stationed there if their sole duty was to defend the comparatively short stretch of coast line that forms the German Empire's bulwark on the North Sea?

Heligoland, like the newly created fortresses of Borkum and Westerland Sylt, was a menace, directed principally against Great Britain and the British Empire.

And by a strange freak of navigation the Diomeda had dropped anchor in South Haven. Possibly had the lighthouse been showing its powerful light Hamerton might have picked up his position even in the thick, drizzling rain; but, in accordance with notices supplied to mariners by the German Admiralty, the light was extinguished whenever night operations were in progress in the vicinity of Heligoland. The leading lights on Sandinsel and the lamps at the extremities of the Moles had likewise been temporarily discontinued; yet in spite of these disadvantages, the German authorities had the mortification of knowing that a small craft, unpiloted and unseen, had crept up to the anchorage in the dead of night.

On the face of it there could be no other explanation than that the crew of the yacht were spies. The failure on their part to show a light under the bowsprit by night, or hoist their national ensign to the masthead by day, was in itself suspicious; and, left to their own resources in their temporary prison, Hamerton and Detroit agreed that the action of the German authorities was to a certain extent justifiable.

"Directly we explain matters to the commandant we'll be released," said Hamerton; "but I don't see the fun of having to give explanations to that arrogant sweep of a major."

"Nor I," added Detroit. "And I guess I'd just like to have half a dozen rounds with that yellow-haired lieutenant. I'll bet the other fellow is having a high old time rummaging our belongings."

The Sub did not reply. Again the thought of what might happen if the compromising Schwartz-Kopff torpedo book were discovered flashed across his mind. He almost wished that he had tossed the thing overboard, for he had not had an opportunity of reading it and committing the salient facts to memory, and its recovery by the German authorities would mean not only that the information was lost to the British Admiralty, but that the crew of the Diomeda would be placed in a very awkward predicament.

"It's real rotten being hung up here," continued the American. "See, the sun is shining again." He pointed towards the single-barred window four feet above their heads, through which the sunshine was streaming brilliantly. Even as he spoke the shaft of light was suddenly obscured, and a dull whirring sound came from without.

"Here, give me a leg up!" exclaimed the Sub. "Bend down, and I'll get upon your back."

Detroit immediately complied, and with considerable agility Hamerton clambered on to his friend's shoulders.

With hardly an effort the muscular American stood upright, in spite of the Sub's bulky proportions, and Hamerton was able to grasp the bars of the window and look out.

He was not disappointed in what he saw. An enormous military Zeppelin had just descended, and was being guided by several hundred soldiers along the sandy stretch between the Unterland and the sea. The afterpart, with the twin propellers and rearmost nacelle, was alone visible from the Sub's outlook. The car contained a Krupp seven-point-five-centimetres automatic gun, firing twelve-pounder shrapnel shells specially intended for use against hostile aeroplanes. At a range of four thousand yards the flying portions of the shell covered a radius of twenty yards, while the disturbance of the air caused by the explosion of the projectile was calculated to imperil the equilibrium of any heavier-than-air craft within a hundred yards of the point of detonation.

On the upper side of the rounded aluminium envelope was a small platform on which stood another automatic gun on a vertical mounting, so as to be able to fire at any aeroplane that might venture to assail the Zeppelin from above.

To each of these platforms were attached two small cigar-shaped ballonettes, fitted with life-lines. These were obviously intended to act as aerial life-buoys should disaster overtake this mammoth of the air; but what struck Hamerton most forcibly was the sight of a couple of officers standing in the rearmost nacelle and actually smoking cigarettes.

"These fellows have a supreme faith in the nonporosity of their gasbag," he thought. "With that immense volume of hydrogen, and the fate of previous Zeppelins in their minds, I am surprised that they dare risk such a thing. I wonder if they've discovered another gas of the same or greater lifting-power than hydrogen? Or perhaps some of the German savants have found a means of rendering hydrogen non-inflammable. I'd like to find out, by Jove!"

The Zeppelin came to a standstill with her nose almost touching the Waalhorn monument, and her tail within a few feet of the disused lifeboat slip. With the utmost celerity several lengths of hose were coupled up, and the work of replenishing the petrol tanks was begun. The two officers who were smoking descended from the nacelle and walked away in the direction of the Oberland, a mechanic gave the signal, the hoses began to swell, and the liquid, under the force of gravity, poured into the storage tanks.

The sound of approaching footsteps caused Hamerton somewhat reluctantly to descend. Detroit, red in the face, had already begun to realize that, muscular though he was, the Sub's weight could not be borne with equanimity.

The door was unlocked and thrown open. A file of marines with side-arms entered, headed by a sergeant. Without a word the men surrounded the two prisoners; the non-commissioned officer pointed meaningly towards the open door.

Through the cleanly kept streets of the Unterland the two comrades were hurried, then up the zigzag path communicating with the plateau known as the Oberland, where the larger portion of the residential buildings was situated. Hamerton recognized the old and the new lighthouses and the Bull Beacon from sketches on the Admiralty chart; but he was somewhat surprised to find that even in the short journey between the Unterland and the Government House there were no less than ten large guns in armoured casemates, searchlights galore, and a network of ammunition lines, on which ran trucks actuated by electric power.

In front of the Government House stood a lofty flagpole, from which fluttered the German national ensign. One thing he remarked was that every passer-by saluted the emblem of the Mailed Fist.

"Guess I'll bet you a dollar we're free in less than twenty minutes," said Detroit to his comrade, as they were marched up the stone path towards the commandant's dwelling.

Before Hamerton could make any remark, one of the hitherto silent and stolid marines turned his brass-helmeted head and added: "I don't tink!"

CHAPTER VI

Von Wittelsbach's Plan

General Heinrich von Wittelsbach, the commandant of the garrison of Heligoland, was a man of fifty-five years of age, of medium height, corpulent and choleric. His iron-grey hair, growing low on his forehead, literally bristled; the ends of his bushy eyebrows well-nigh touched the tips of his upturned moustache, which as the result of years of training outvied those of his Imperial master.

Von Wittelsbach was a pronounced Anglophobe, and on that account was a great favourite with the German Crown Prince. On the other hand, his hot-headed outbursts against everything British were discountenanced by the Kaiser, who took a more level view of things. The time was not yet ripe for Germany to measure steel with the nation that in the Teutonic mind formed the sole barrier to colonial expansion, and for the present it was considered advisable to remove Von Wittelsbach to a more remote sphere, where his activities could be prosecuted in secret and with an energy that suited the old veteran's ideas to a nicety. So the general was placed in command of the important military and naval station of Heligoland.

Like most German officers Von Wittelsbach was badly attacked by the espionage mania. In his eyes every man not in German uniform was a spy. In one or two instances he had burned his fingers rather badly, for, having caused supposed spies to be arrested and sent to the Supreme Court at Leipzig for trial, he failed to make good his case. A section of the German Press, loath to miss a chance of revenge upon the autocratic Von Wittelsbach, held him up to ridicule. The general vowed that the next time there would be no mistake, and took the precaution of obtaining authority to try supposed spies summarily, instead of sending them to the Saxon town.

Still attended by their armed guards, Hamerton and Detroit found themselves in the room where the preliminary examination was to be held. It was to be a trial behind closed doors, for in addition to the prisoners and the file of stolid marines the only persons present were General Heinrich von Wittelsbach, Major Karl von Schloss, Naval-Lieutenant Schwalbe—the officer who had effected the arrest—and a military secretary.

The room was a large one, simply furnished as an office, the only attempt at ornamentation being the presence of a large bust of the Kaiser set in a niche above the mantelpiece. At one end of the room stood a table about twenty feet in length and fifteen in width, the top being carefully covered with a green baize cloth. Had that covering been removed, Hamerton would have been able to see a chart of the North Sea, the land being shown in relief. On this, from information supplied by trustworthy agents, the position of every unit of the British fleet was recorded as quickly as reports came to hand. Every battery, aircraft station, regimental depot, and railway communication was carefully shown, so that a reliable and up-to-date plan lay ready to hand when "The Day" came.

The President made no attempt to address the prisoners in German. Schwalbe had already acquainted him with the fact that one of the accused spoke that language fairly well, but Von Wittelsbach told him that he would not listen to a vile smattering of the language of the Fatherland by one of these rascally Englishmen. So all communication between the President and the prisoners was to be made through the medium of the former's secretary.

"You are accused of unlawfully committing acts of espionage against the imperial defences of Heligoland," announced the secretary. "Accused, what have you to say?"

There was a few moments' silence, broken only by the scratching of a pen as the secretary recorded the replies.

"Ach!" ejaculated Von Wittelsbach, rubbing his hands. "Good! Look up his record, Herr Schwalbe."

The lieutenant took down a leather-bound volume, and Hamerton was somewhat surprised to hear the record of his various appointments read out.

A shade of disappointment flitted over the commandant's face when he heard that the whole of the prisoner's sea time had been spent on tropical stations. He had hoped that this English officer belonged to one of the ships of the Home Fleet.

"And your name?" demanded Von Wittelsbach through his secretary, addressing the American.

"Oswald P. Detroit, aged nineteen, American citizen, native of Richmond, Virginia, U.S.A. Say, my man, any further information you may require will be trotted out with the utmost celerity."

The secretary stared, unable to grasp the full meaning of the verbosity of the accused. Lieutenant Schwalbe turned and whispered into the President's ear.

"An American?" repeated Von Wittelsbach, hardly able to master his surprise. "Are you certain?"

Receiving an affirmative reply, the President leant back in his armchair and reflectively stroked his moustache. Here was a new phase, one that he had not bargained for.

"Remove the accused," he ordered. "The evidence for the prosecution is not yet complete. Inform them that they must be kept in confinement till Friday next."

"I presume we will be given an opportunity of communicating with our friends?" asked Hamerton.

"No," he replied; "spies are not entitled to any consideration of that description. What news we think fit to give to your friends in England—and America—will be imparted in due course. Marines, remove the accused."

General Heinrich von Wittelsbach waited till the sound of the retiring file of marines had ceased. He was still pondering over the scheme that had suddenly suggested itself. His subordinates, knowing his fiery disposition, stood motionless, waiting for their commandant to speak.

"Very good, sir," replied the lieutenant, showing remarkable energy as he made for the door.

"Now, Von Schloss," continued the commandant, as soon as Schwalbe had taken his departure. "We will discuss this matter. I may as well mention that I had no idea that one of the prisoners was an American subject. You think his statement is correct?"

"The best thing we can do is to proceed with the case against both prisoners. To release one would be prejudicial to the interest of the Fatherland, even though he be an American—which I doubt."

"What, then, sir, do you propose to do to satisfy any enquiries on the part of the United States Ambassador at Berlin? There is bound to be an outcry; these Americans are so upset over little trifles."

"There I agree, Herr Major. You say that the prisoners have not given their names to anyone belonging to the garrison before appearing here? No? Ach! I have it. Of course they are spies?"

"Undoubtedly, sir. The mere fact that they came in under cover of night, evaded our patrol boats, and brought up close to our latest submarines is suspicious. Add to that the fact that they hoisted no ensign and made no attempt to communicate with the harbour officials, and the case is as clear as daylight."

"Rutter," said the general, addressing his secretary, "what names did the accused give?"

"That is a mistake. Cross the names from your notebook. Now tell me a common English name."

"Then enter the names of the prisoners as John and Wilhelm Smith, brothers, of London."

"John and William Smith, sir," corrected the secretary, and without evincing the faintest surprise he made the alterations according to the commandant's directions.

"But the yacht, sir?" expostulated Major Von Schloss, who was beginning to see the drift of his superior's plan.

"That I have not overlooked, Herr Major. Wait until Lieutenant Schwalbe returns. Meanwhile, Rutter, let me have those papers for signature."

The secretary handed his chief a bundle of documents, and stood ready with a blotter. Von Wittelsbach did not shirk his work. Unlike many highly-paid British Government officials, who perfunctorily place their signatures to documents while hardly condescending to acquaint themselves with the nature of their contents, the commandant carefully read every paper before putting his signature to it.

At the same time he was no blind devotee of red-tapism. Amongst that pile of papers there was not one that could be regarded as purely formal; every one had some direct bearing upon the vast establishment under his command.

Before this particular task was completed Lieutenant Schwalbe returned, accompanied by Lieutenant Dort, the officer who had been left in charge of the Diomeda. Seeing their superior engaged, they drew themselves up and stood stiffly at attention till the last signature had been written and the documents handed back to the secretary.

"I have had the yacht ransacked, sir, and nothing incriminating has been found."

"Unless I except the charts—they're useless as far as the defences of the island are concerned—a telescope, and a camera."

"Yes, sir, they will be dry in less than half an hour; but the views are only of some English and Dutch fishing boats."

"And, Herr Dort, another matter. Have all traces of your search on board the yacht removed, and make all snug. Directly it becomes night detail a torpedo boat to tow this craft towards Norderney Gat. When within a league or so of the lightship cut the yacht adrift."

"No," replied the commandant after a moment's reflection. "No; only cast her adrift with all sail set. Report to me in the morning. Now, Major, you see what I am aiming at, and what I mean to carry out?"

"Then draw up a report to the effect that two Englishmen, John and William Smith, were detected in the act of spying upon the fortifications of Heligoland. Give a description as different as possible of the prisoners, and any other details that may tend to remove suspicion as to their actual identity. Have the report telegraphed to Berlin, and say I propose to deal with the accused by virtue of the power vested in me by the recent Imperial decree. Send a similar dispatch to Reuter's agent, and the news will be all over the world in less than half an hour from its receipt. I think this plan will suit admirably; do not you, Herr Major?"

"But the prisoners, sir?" asked Von Schloss, who, although the task was repugnant to him, had no option but to obey orders. "How long do you propose to keep them in detention?"

"A matter of two years. Ere then will come 'The Day'. After that it matters little whether this John Hamerton be John Smith or otherwise. Now, gentlemen, you know your orders; above all, impress upon every man in this affair the utmost importance of secrecy and reticence. Tell them to spread the report that the two Englishmen are to be released to-night and taken clear of the island in their yacht by one of our torpedo boats. Decide upon the details between yourselves, but in any case report to me early to-morrow morning."

CHAPTER VII

Official Hindrances

On the day following the preliminary examination of the two alleged spies the London evening papers published with double-leaded headlines:

"Hamburg, Tuesday, 5 p.m. Telegraphic advice from Heligoland reports that two Englishmen, giving the names of John and William Smith, and aged about forty, were arrested on a charge of espionage early this morning. It is alleged that the prisoners, taking advantage of a dark and rainy night, eluded the cordon of patrol boats and succeeded in landing upon Sandinsel. When arrested they were in the act of photographing a highly important part of the defences. The open motor boat in which they visited the island has been seized, and drawings and photographs of various government establishments and ships were found concealed behind the petrol tanks. The accused, who admitted that they were in the employ of the British Intelligence Department, will be tried summarily by the Governor of Heligoland, General Heinrich von Wittelsbach, on Friday next. It is understood that the British Consul at Bremen has applied to have access to the prisoners."

This announcement naturally caused a great deal of comment amongst the British public. The general opinion was that the alleged spies knew the risk they were running and must take the consequences. Various attempts were made on the part of the press to discover the identity of John and William Smith. Enquiries at the Naval Intelligence Department gave no tangible result. The authorities there expressed their ignorance of the whole business.

The morning editions on the following day came out with highly coloured reports emanating from imaginative German journalists; but the only particle of truth was the information that the request of the British Consul at Bremen had been refused. In order to give the accused every possible advantage a military officer of high rank had been dispatched from Berlin to act as "prisoners' friend". Owing to the possibilities of important military and naval secrets being disclosed at the impending trial, the proceedings were to be conducted behind closed doors.

Even with this announcement the Great British Public maintained its customary apathy. Had some Polish revolutionary been tried under similar circumstances in far-off Russia a certain section of the British Press would have howled itself black in the face at the injustice and inhumanity of the proceedings. In this instance it was merely an attempt on the part of two venturesome Englishmen to gain notoriety at the expense of risking our amiable relations with a friendly State. John and William Smith must take the consequences.

"A ketch yacht, named Diomeda, has been brought into the port of Delfzyl by the Dutch steam trawler Hoorn. The master of the trawler reports having found the yacht derelict, with all sails set, nine miles N.N.W. of Norderney. There are three yachts named Diomeda in Lloyd's Register, but from the Dutch skipper's description the abandoned yacht is the property of Mr. Octavius Valerian Smith of Lowestoft."

At ten o'clock a telegram was handed in at the London offices of The Yachtsman's Journal. It was from that paper's Lowestoft correspondent:

"Smith, owner Diomeda, reports yacht chartered Sub-Lieutenant Hamerton, R. N. Owner starting Delfzyl immediately. Shall I accompany?—Stirling."

The editor thought over the message for some minutes. Here was a chance of obtaining copy direct from the scene of the disaster. He would dearly like to steal a march on his contemporaries. The mystery might prove far more exciting than it looked according to the morning dailies. But there was the expense; The Yachtman's Journal had not a large amount of capital behind it. Of course, Stirling would not want a large sum for the trip, but there were the travelling expenses.

A thought struck him: why not consult his friend Thompson, the news editor of the influential Westminster Daily Record?

"Is that you, Thompson?" he asked on the telephone after several vain attempts to get through.

"Yes, old man," replied the editor of The Westminster Daily Record, who recognized his friend's voice.

"Just heard she was chartered by a naval officer. I fancy there's something behind this. Stirling, my Lowestoft correspondent—a smart, reliable fellow; I know him personally—has just wired to ask if he should go to Holland."

"Hanged if I can see what you are driving at, old man. Send the young chap by all means if you want to. By the by, what's the naval officer's name?"

The editor of The Yachtsman's Journal diplomatically ignored the latter question.

"I'd send him like a shot," he replied, "only it's a question of, £, s., d. What do you say? Will you guarantee half the expenses? It's a chance of a good scoop, the information to be solely for our joint use."

"No," he said brusquely; "can't be done. It's not of sufficient interest to the general public."

"H'm—well, I'll tell you. Send your man. If the stuff's of use to us we'll pay all expenses. Anything out of the ordinary he can wire us. If there's nothing meriting notice we'll only pay a quarter of the expenses. Game?"

Something seemed to whisper in the mind of the Yachtman's Journal editor: "Accept his terms. You'll be sorry if you don't."

"Right! Ring off," was Thompson's laconic acceptance, and he resumed his chair in order to tackle the final proofs of the evening's issue.

Shortly after eleven Gordon Stirling, amateur yachtsman and yachting correspondent of The Yachtman's Journal, received a wire from town:

"Proceed to Delfzyl. Wire report if urgent. All expenses guaranteed.

"EDITOR."

Stirling gave a whoop of delight when he read his sailing orders, and considerably astonished his landlady by executing a dance round the room. Perhaps such an exhibition was pardonable in a high-spirited youth of nineteen, but Mrs. Grimmer surveyed her paying guest with evident concern and unrestrained curiosity.

"It's all right, Mrs. Grimmer," he explained. "I'm off to Holland for a few days."

"No, by steamer. I'll have to leave here before twelve. Now I must pack my bag. You might ask Dick to take a note round to Mr. Smith for me."

The note was simply to the effect that the writer had made arrangements to accompany the owner of the Diomeda to Delfzyl, and would meet him at the station at 12.15.

This written and dispatched, Gordon Stirling proceeded to cram a variety of clothing into a serviceable leather bag, regardless of how they were stowed so long as the bag could be closed.

Stirling was very fortunately situated. He held an appointment at Lowestoft under the Inland Revenue; he had just started his annual leave and was meditating a trip on the Broads. To that end he had drawn a small sum from the savings bank, to which was added the greater part of his last month's salary, and thus he found himself with a little over twenty pounds in his pocket and fourteen days in which to spend it. Here was a chance of having a holiday on the Continent, with the prospects of getting hold of some exciting news and recouping all his expenses. Truly he was in luck's way.

"Glad you managed it," was Octavius Smith's greeting as the two met at the railway station. "Look alive and get your ticket. Single to Harwich only, mind."

Octavius Valerian Smith was a striking contrast to his companion, for Stirling was a short, thick-set fellow with a perpetual beam on his rounded features, whereas the owner of the Diomeda was over six feet in height and as slender as the proverbial barber's pole. It would be difficult to describe his complexion. Exposure to the salt-laden breezes of the North Sea had tanned his features to a brick-red colour. In spite of his approximation to Euclid's definition of a line he was muscular and sinewy, and as hard as nails. Possessed of small private means, he augmented his income by writing, and made a fairly good thing out of it. Few of the hundreds of love-sick maidens who read the romantic stories appearing in various women's journals under the name of "Reginald Beaucaire" would recognize their favourite author in the person of the taciturn-featured O. V. Smith.

Yet even in the flood tide of literary success there are irritating counter-eddies—periods of pecuniary embarrassment. The owner of the Diomeda, always careless with his money while he possessed any, had a few days before found himself in low water.

This inevitable condition compelled him, much against his will, to charter the yacht to Sub-Lieutenant Hamerton, and now he was on his way to recover his most precious possession from the hands of the Dutch salvors.

"You've got the yacht's papers, I hope?" asked Stirling as the train glided out of the station.

"Then how do you propose to establish your identity? The Dutchmen won't feel inclined to hand the Diomeda over until you prove you are the lawful owner."

"If you're satisfied I am," remarked Stirling. "By the by, what were those fellows like who chartered her?"

The Diomeda's owner proceeded to give a detailed description of the unfortunate Hamerton and his chum Detroit. This done, he took up a newspaper and began to read, while Stirling wrote an account of the two supposed victims for the benefit of the patrons of The Yachtman's Journal.

"By the by," said Stirling, "is there any more news about that spy case? I suppose the two men are no relations of yours?"

"We all belong to the great and noble family of Smiths," replied the literary man oracularly. "It's a bit confusing at times, especially when one receives a blue envelope intended for a very distant relation. I've had some."

Octavius once more buried himself in his paper. Stirling resumed his scribbling, and thus the time passed until the train reached Harwich.

It was half-past eleven on the Thursday morning when Smith and his companion arrived at Delfzyl. Both were dead tired, for the tedious railway journey, especially between Zwolle and their destination, was the last straw.

The good folk of Delfzyl were evidently thought-readers, for directly the Englishmen left the station they were surrounded by a gesticulating mob, every man, woman, and child in the crowd pointing out the way to the quay where the Diomeda lay.

It was low tide, the Dollart and the estuary of the Ems River were one expanse of sand and mud. The yacht lay against a staging of massive piles. On the quay was a line of stolid Dutchmen, all peculiarly garbed in quaint cutaway coats, baggy trousers, klompen or wooden shoes, and dull-black high-crowned hats. There they stood, hands in pockets, long pipes in their mouths. Hardly a word was being spoken. They seemed perfectly content to stand on the quay-side and gaze meditatively at the mysterious craft that the steam-drifter Hoorn had brought in.

The arrival of the Englishmen with their attendant throng roused the lethargic Dutchmen. They too added their voices to those of their fellow townsfolk.

"Thank goodness the yacht seems all right," ejaculated Smith fervently. "Let's get on board. It's the only way to escape the babel."

The Diomeda looked exactly as if she had been lying on her own moorings in Lowestoft harbour. Her sails were neatly furled, her flemished ropes were exactly where they ought to be, her decks had been washed down, her brasswork glittered in the sunlight.

"How are we going to get on board?" asked Stirling, regarding the twelve-foot drop from the stage on to the deck with apprehension. "Besides, the cabin is locked, and you haven't the keys."

"I'll manage it," replied the owner confidently. "Stand by and throw me down the luggage when I reach the deck."

A score of voices joined in giving him directions. Forty hands or more pointed in the direction of the red-tiled house, with green doors and window frames, where dwelt Cornelius van Wyk, the guardian of the maritime interests of Delfzyl.

"You do the tongue-wagging, old chap," said Smith to his companion as they were ushered into a spotlessly clean parlour. The mob of curious townsfolk, debarred from entering by the sturdy demonstrations of the harbourmaster's hus-vrow, lapsed into comparative silence. Pipes were filled, precious matches handed round, and the expectant throng waited for the Englishmen's reappearance.

The two travellers had to wait nearly an hour for the official's appearance. Van Wyk had gone down the estuary on duty. Meanwhile his wife brought refreshments, for which both men were truly thankful, as they had eaten nothing since leaving The Hook.

"You, Mynheer, are the owner of this yacht?" asked the harbourmaster on his return. He spoke excellent English, with an East Anglian accent, acquired by reason of his frequent intercourse with vessels hailing from the ports of Norfolk and Suffolk. "You, of course, have the papers?"

"They were in a cupboard on the port side of the for'ard bulkhead," asserted the owner.

"Is it likely that two men should disappear and take the yacht's papers with them?" asked Smith.

"Curious things happen at sea," he said. "Dirk Apeldoorn, the mate of the Hoorn, told me the yacht had all her sails set. The tiller was not lashed; her dingy was towing astern. She was pointing towards the land, first on one tack and then on the other. It was this strange thing that attracted his attention. But, Mynheer, why should the papers disappear? Without them who can tell who is the owner?"

"I have these," replied Smith, pulling out several documents relating to the transaction between Hamerton and himself.

"Heaven forbid that I should doubt you," exclaimed Van Wyk, "but duty is duty. I have the keys; I am authorized to receive the money due for salvage; but before I can allow you on board I must have a declaration on oath that you are in truth the owner, and a copy of the yacht's papers."

"It is easy to say so, Mynheer. I might say I am the Prince Consort, but without proof——?"

"This looks like a week's business," said Smith savagely, as the twain regained the cobbled street. "I suppose the old chap is within his rights. We'll have to write off to the Board of Trade for duplicates of the Certificate of Registry and the Declaration of Ownership."

"And make a sworn declaration before a lawyer that you are indeed Octavius V. Smith," added Stirling.

Two days later the owner of the Diomeda skipped out of the post office at Delfzyl, holding in triumph a blue envelope with the inscription "On His Majesty's Service". Ten seconds later his exultation was changed into deep disgust, for the Board of Trade authorities had asked for additional information. They had already heard that the yacht had been picked up practically intact. Her papers were known to be on board when she left Lowestoft; what explanation, they asked, had Mr. Smith to offer for their disappearance? Pending satisfactory evidence the Board declined to issue duplicate certificates.

Time was pressing. In desperation Octavius Smith penned a lengthy epistle explaining that he was in utter ignorance of the fate of the documents, and that the harbourmaster of Delfzyl had flatly refused to give up possession of the Diomeda until such documentary evidence were forthcoming.

Two more days passed. Then, with a promptitude surprising for a British Government Department, the duplicates arrived.

"Ah! That is all in order," exclaimed Mynheer van Wyk. "All that is now required is to pay the salvage. Then you take possession."

"I see," agreed Octavius Smith, though not with any degree of enthusiasm. He had no doubt that the executors of the supposed deceased Jack Hamerton would ultimately pay all expenses in connection with the redemption of the Diomeda, but for the present he would have to be out of pocket. "What is the value of your yacht?" asked the harbourmaster, who also held the office corresponding to that of British Receiver of Wrecks.

"That may be so," he remarked; "but I see no copy of the bill of sale. How am I to know that this is the value of the yacht?"

"Then why in the name of thunder didn't you ask me to get it with the other papers?"

"Every mortal thing. Wants a copy of the bill of sale to prove how much I gave for the yacht. Luckily I have that at home. I'll wire for it. This petty officialdom is enough to make a fellow wild."

"I thought petty officialdom existed only in England. Such used to be your opinion," said Stirling slyly. "Buck up, old man, we'll soon be afloat. By the by, here is a newspaper. They've given these sixty-ninth cousins of yours pretty stiff sentences, by Jove!"

Octavius Smith glanced at the printed matter, "'Pon my word, they have," he replied. "After all, they were asking for it."

CHAPTER VIII

Sentenced

The eventful day fixed for the trial of the two alleged spies came at last. Hamerton and Detroit found themselves, not, as they expected, in a crowded court, bristling with lawyers, witnesses, and keenly interested spectators, but in the same room in which the preliminary examination had taken place.

The court was modelled on the lines of the tribunal in the Zabern incident. It was virtually within closed doors, the military and naval element constituting judges, prosecutors, and witnesses.

Only Von Wittelsbach's warped sense of Imperial devotion, coupled with his cast-iron belief that the accused were really spies, urged him to proceed with his plan. To him it was inconceivable that two foreigners should be able to navigate a yacht in thick weather and in the dead of night right up to the strictly prohibited anchorage reserved for the exclusive use of the "Mosquito" flotilla of the Imperial German Navy.

He was, of course, unable to form any definite idea of the amount of important information that the alleged spies had acquired. They might have gained priceless secrets during the short period the yacht was at anchor under the lee of Heligoland or they might have had their plans nipped in the bud by their prompt arrest.

In any case he concluded that the release of the accused would result in a menace to the safeguards of the empire, and that must be avoided at all costs.

It cannot be said that his immediate subordinates would have been completely in accord with his ideas had the true facts been known to them. Even Von Wittelsbach had his doubts as to whether he could overcome their sense of justice and fair play. On the other hand, the officers—imbued from the day they first donned the uniform of the German Empire with the outstanding idea that a soldier must unquestionably obey orders—were not likely to cause obstacles to the commandant's plan could he but impress upon them that the prisoners were spies, and as such a serious danger to the welfare of the State.

Von Wittelsbach was quite convinced in his own mind that once the alleged spies were convicted they would be kept out of mischief till the necessity for strict secrecy regarding the naval and military preparations of the Fatherland ceased to be of paramount importance.

Great was Hamerton's and his companion's consternation when they found themselves indicted under the names of John and William Smith, on a charge of unlawfully obtaining information of the Sathurn, Waalhorn, and Kordberg batteries situate upon the Island of Heligoland; the Braaknocke, Kalbertan, and Olde Hoven batteries on Sandinsel Island; and the submarine and torpedo-boat harbours in South Haven, adjacent to the said Island of Heligoland, such acts being unlawful and prejudicial to His Imperial Majesty the Emperor and the German people.

For three hours the tedious case dragged on. There was a call for witnesses for the defence, and, none being forthcoming, the president asked if either of the accused wished to give evidence on his own behalf.

Through the interpreter Hamerton strenuously denied that either he or his companion was guilty of spying; that by a sheer fluke they found themselves in a prohibited anchorage; and that, had they been asked, they would at once have tendered their apologies and set sail.

"As regards the book dealing with the Schwartz-Kopff torpedoes," continued the Sub, "I can easily account for its being in my possession. It fell from the clothing of a German seaman, Pfeil by name, whom we rescued after falling from your torpedo-boat destroyer S167. No doubt the man, if produced, will corroborate my statement."

Von Wittelsbach looked astounded. This admission took him completely by surprise. Then with an effort he concealed his astonishment and ordered the court to be adjourned for luncheon. In the interval he sent for Lieutenant Dort.

"What is this about the Schwartz-Kopff manual?" he asked. "Where is the one you found on the yacht?"

"The prisoner says he had one. You must have overlooked it. And now that accursed yacht is drifting in the German Ocean with a priceless secret stowed away on board. I would give twenty thousand marks to get her back again. Hasten and order the fourth flotilla to cruise in search of her."

"It is already too late, sir. The yacht was picked up by a Dutch trawler and towed into the Dollart. I thought——"

"You thought, dolt!" interrupted the commandant angrily. "Yet it may not be too late. Find out at what port this yacht is lying. Get our agent there to keep us well-informed of all that occurs. The craft will doubtless be sailed back to England. After to-day you will cruise off the Dollart. It will not be necessary to keep out of sight of land provided you raise no suspicion. Two torpedo boats will be sufficient, or even one. Directly the yacht sets sail our agent will wire to me. I will communicate with you by wireless if you do not observe her leaving port. Then do something that will enable you to take possession of the vessel without exciting undue attention."

"Excellent. Mind you do it; but take care that she is not sunk. Then tow her back here. We will then be able to discover the all-important book that this fool of an Englishman has babbled about."

Von Wittelsbach was extremely reticent during the luncheon interval. In his innermost mind he devoutly wished that he had exercised more discretion before issuing orders that Hamerton and the American were to be arrested as spies. But the die had been cast. He had taken the first step. His iron will must see the business through. And then the complication in connection with the torpedo manual? He realized that if the book still remained on board the yacht it would sooner or later be discovered. To allow a confidential book like that to fall into the hands of a foreign Government—the British, above all!—was bad enough. Add to that the consternation that the discovery of the book would occasion; and it became fairly evident that there would be embarrassing questions raised by parties interested in the supposed deceased crew of the yacht. Hence his anxiety to regain possession of the Diomeda.

When the court reassembled it was merely to conclude proceedings. The prisoners were found guilty and sentenced to five years' close confinement in the fortress of Heligoland.

A confidential report drawn up in Von Wittelsbach's own handwriting was dispatched to the Admiralty at Berlin, and an official account of the trial sent to the Press. The latter had been carefully censored by the commandant. He felt tolerably safe, except for the fact that the Diomeda was not back in South Haven at Heligoland. His secret was shared by five men only: the others present in the court were, owing to their inability to understand English, ignorant of the material facts of the case. Each of those five he thought he could rely upon, since their career depended solely upon the commandant's periodical reports to the German War Office.

And strangely enough his motives were actuated by a hatred of the British Empire; his deep reluctance to swerve from a resolution once formed, and an overwhelming desire to serve the Fatherland, completely overruled all sense of fair play.

CHAPTER IX

On the Scent

"Thank goodness we are on board at last!" exclaimed Octavius Smith, as the two chums entered the companion-way of the Diomeda. "Those Dutchmen seem the essence of honesty. As far as I can see not a thing is missing."

"Of course; but I mean since the yacht was picked up. We'll have an overhaul to make sure."

"Strikes me I am not setting the Thames on fire over this business," remarked Stirling ruefully. "I've sent off three separate reports, but, between you and me, they are not startling enough to merit the expense of sending me out here. I suppose I lack journalistic ability to put the finishing touches to a rather bald account of the accident."

"Unless his theories are contradicted in the next issue, my dear chap. Then there's a breeze. But when do you propose sailing?"

"As soon as we get a fair slant of wind. I've no mind to go plugging against a south-wester for a week on end."

"I hope to goodness we get a fair breeze before that, or my leave will be up. But let's to work! We'll examine everything carefully and make an inventory of all that belongs to the late charterers. We'll turn out the contents of that rack first."

"Hold on; here's the logbook," exclaimed Smith. "I wonder if Hamerton—poor chap—entered anything in it. By George, he has!"

The entries extended up to 1 a.m. on the fateful Tuesday morning. The sighting of the Norderney light, the error in the compass course, and the fact that the yacht had been steered in a north-westerly direction to claw off the sandbanks and the mouth of the Elbe were set down in the Sub's handwriting.

"Seems funny," remarked Stirling thoughtfully. "They speak of a strong breeze, and sailing under reefed mainsail, close-reefed mizen, and storm jib. That is early on Tuesday morning. That same evening the yacht is picked up forty miles in almost the opposite direction to the course shown in the log. Her reefs were all shaken out, and she had her large jib."

"Then why wasn't that part recorded in the log? Hamerton seems to have been most conscientious in writing it up. Every hour there is a fresh entry, yet at 1 a.m., when it is blowing hard, there is a sudden break."

The work of clearing the rack on the port side of the cabin proceeded apace. It was not a congenial task separating the effects of the two missing men from such articles as belonged to the owner.

"What do you make of that, old man?" he asked, holding up a carefully folded newspaper.

"Nothing," replied Smith laconically. "I can't make head or tail of German: never could, and don't want to—why?"

"Look at the date: Tuesday the 10th inst. Now how would Hamerton get hold of a German newspaper without going ashore? Mind you, this is the date on which the accident is suppose to have occurred."

"Hardly likely. He had been out in the North Sea for a week before he picked up the yacht. Directly he brought her in here she was handed over to the harbourmaster. I think I'll see Van Wyk. He may be able to throw some light upon the matter."

"Wait till after lunch. He's bound to be out somewhere. Look here! I'll finish this sorting business; suppose you carry on and fry that steak."

"Righto!" replied Stirling, and reaching for a paper parcel containing a pound of very juicy steak he disappeared into the fo'c'sle.

Very soon the "Primus" stove began to roar, and an appetizing odour filled the interior of the little craft.

Smith cleared away the pile of articles from the rack and proceeded to prepare the table for the meal. In the midst of his activities the sliding door of the fo'c'sle was thrust back, and Stirling's head and shoulder's appeared, backed by a cloud of vapour with which the little compartment was filled.

"Blessed if I can understand what's wrong with the oven," he exclaimed, wiping the tears from his eyes, for the smoke had caused them to water freely. "It went all right for about five minutes, then there was a regular burst of beastly smelling smoke."

"Let me have a look at it," said Smith, with grim determination in his voice. "I'll soon see what's wrong. Open that forehatch, old chap, and let's get rid of the infernal smoke."

The raising of the hatch and the accompanying cloud of vapour was the signal for a chorus of exclamations from the line of phlegmatic Dutchmen on the quay, who, for want of something better to do, were passing the time in meditative contemplation of the Diomeda. The roaring of the stove deadened all external sound, but a minute later the occupants of the fo'c'sle were saluted by a deluge of water. Imagining that a fire had broken out on board, two of the good folk of Delfzyl had adroitly poured a couple of buckets of water down the forehatch.

Hurried explanations and a profound apology from the well-meaning Dutchmen followed. The crew of the Diomeda once more dived below to change their saturated garments.

"Now let's have another shot at it," said Smith, as he removed the steak, soaked with salt water, to a safe distance from the stove. "There's something fizzling away in the double bottom. Hand me that screwdriver, my young friend."

It was an easy task to remove the front of the stove, revealing a deep cavity in which was a steaming mass of paper.

"That's the cause of it all," announced Octavius Smith, as he hooked out the offending object. "It's a book. How on earth did it get there?"

"Is it?" grunted Smith. "I'll swear it wasn't there a fortnight ago. Anyway, I don't want to get into trouble about it in case we have to put into a German port. Heave the blessed thing overboard."

Smith looked at his companion with surprise depicted on his features. Stirling was generally of a complaisant disposition.

"Why not, you silly cuckoo? That will be enough to get us five years in a fortress, like my sixty-ninth cousins, John and Bill Smith. I'm not taking any, thank you."

"All the same, I don't think I'll throw it overboard. I've got to go ashore for more steak; we can't possibly eat that stuff—it's smothered with salt water. I'll pack up the book and send it to my address by registered post."

"Please yourself," retorted Smith ungraciously. "So long as it isn't on board I don't mind, but I'm hanged if I can see what possible use it can be to you."

"Never know your luck," replied Stirling as he backed into the cabin. "I wonder if there's any brown paper on board."

"Why not dry the blessed thing first?" asked Smith, always more thoughtful for others' pockets than he was for his own. "It won't cost so much for postage."

"Not a bad idea," was the reply. "I'll hang it up under the skylight. That's it. Now for the shore."

Presently Stirling returned with a fresh supply of steak. Once more the stove was lighted, and without further mishap the meat was served.

"Can't help thinking about those fellows who were collared at Heligoland," remarked Stirling.

"Don't see why you need worry about them," said Smith. "I wonder you don't suggest that they are our friends Hamerton & Co. in disguise. Anyhow, they took the risk and failed. Spying is a rotten game, when all's said and done."

"There I don't agree with you. It's an honourable profession. A few men risk their liberty in trying to gain information that in the event of war will save hundreds of their fellow countrymen's lives. It's necessary; both Great Britain and Germany have regular men for the purpose of espionage."

"Hanged if I looked upon it from that point of view; but it seems a downright low trick for a fellow to sell naval and military secrets."

"Rather! There I agree with you. There's a vast difference between a spy and an informer. The first is, I might also say, a humanitarian; the second is a traitor. There's no doubt about it, the Germans have the advantage of us in the espionage line. There isn't a Government building, dock, or battery on the east coast but is known to the German Government. They have spies everywhere."

"Yes, we began at first by letting them off with a caution—gave kindly advice, so to speak. Then they collared some of our secret-service men and gave it to them fairly stiff. We retaliated, and the business became a ding-dong affair, each country increasing the severity of the punishments inflicted upon the spies they detected. But, as you said, five years is a bit stiff."

"Hallo! There's the harbourmaster!" exclaimed Stirling, catching sight of the official through one of the scuttles of the cabin. "I'll ask him about the newspaper."

Both men ran on deck. The crowd of Dutchmen was still in evidence, only the attention of the idlers was directed seaward, A telescope was being handed round, the usually stolid Delfzylers showing considerable eagerness to obtain a loan of the instrument.

"Only a German torpedo boat," replied the harbourmaster. "She is lying off the Dollart, though why I cannot make out."

"Nothing out of the way, is it?" asked Stirling. "It's German territory across the Dollart, isn't it?"

"Aye," replied Van Wyk. "But it is out of the common for a vessel of war to remain there. We are sending out a tug to see if she requires assistance. Look! We have signalled her, but she has made no reply."

"Are you busy for a moment, Mynheer?" asked Stirling. "We've found a German newspaper on board, and we want to know how it got there."

"I do not love the Germans, Mynheer, nor do I ever look at a German paper. I did not put it there. Perhaps your unfortunate fellow countryman placed it there?"

"We think not. We have a reason for asking. Do you think the master of the Hoorn left it on board?"

"There stands Dick Apeldoorn, the mate of the Hoorn," said the harbourmaster, pointing to a little wizened man leaning against a bollard and looking at the torpedo craft through a pair of binoculars. "He was the only man who went below, besides myself. Why not ask him?"

Dick Apeldoorn was positive he had not handled a newspaper for days, let alone a German one. He was a true Hollander, who looked upon the Germans as land grabbers, intent upon overrunning Holland directly they had an opportunity—if they could. He would scorn to be beholden to the Tageblatt for any information.

"That settles one point," remarked Stirling to his companion. "The Dutchman didn't put the paper in the rack of the cabin; it's morally certain Hamerton couldn't; so who did?"

"Speculate upon it, my dear fellow. It's worth a page in The Yachtsman's Journal. Conjecture something startling, only leave me in peace this afternoon. I must knock up a pot-boiler for The Gentlewoman of Fashion, or there will be no shot in the locker when I get home. As it is, this blessed salvage business has seriously depleted the treasury."

Octavius Smith produced a "block" and a fountain pen, and was soon lost to his surroundings in dashing off about a thousand words an hour. When he did work he worked at a tremendous pace, and his companion knew the risk he incurred should he disturb him. So Stirling took up the log of the Diomeda and began to follow it from the time the yacht left Lowestoft on her momentous cruise.

As he read he compared the log with the chart, following Hamerton's notations with the deepest interest.

Suddenly he gave an exclamation of surprise. Smith, deep in his work, went on unheedingly. Stirling had come to the incident of the Diomeda's meeting with the German torpedo boats and the rescue of Hans Pfeil.

"H'm! I wonder if I could get into touch with this fellow Pfeil," he meditated. "Perhaps he might be able to throw some light on the matter. At any rate I'll try. Here's the making of a sensational yarn in the log. But, hang it all! would 'Hans Pfeil, H.I.M. Navy, Germany,' be a sufficient address?"

Something prompted him to reach for the torpedo manual that hung from a hook under the skylight. Its pages were now almost dry, but it required a certain amount of caution to separate the leaves.

"Not much!" retorted Stirling, for on the flyleaf appeared the words: "Hans Pfeil. S.167;" and the counter-signature of the lieutenant commanding the torpedo-boat destroyer. "Not much! Chuck it, for the time being, old man, and listen. I've found out how the torpedo book came on board. At least I think I have. Hamerton mentions that he rescued a seaman washed overboard from a German destroyer. He gives the man's name. It is the same as the one appearing in the book."

"This Hans Pfeil might be able to give us some definite information. Of course I won't say a word about this book."

"I don't see what the fellow can do or say in the matter," objected Smith. "Hamerton in the log says he was transferred to a tramp steamer. That ends the business. Whatever happened to Hamerton and Detroit occurred some time after the incident."

"All the same I'll have a shot at it. I'll write, and pack up the torpedo book at the same time."

CHAPTER X

In the Prison Cell

Immediately after the ending of the trial the two prisoners were separated. Hamerton was escorted through the streets of the Oberland, past the old Frisian church, and lodged in a massive stone building almost adjacent to the north-east angle of the barracks.

During and long previous to the British occupation of Heligoland this building had been used is a fish store. It stood on solidly constructed arched pillars, the entrance being by means of a flight of stone steps protected by a wrought-iron railing. Latterly the space under the vaulted arches had been enclosed by galvanized-iron fencing and utilized as a store for engineering tools and plant. The building above was subdivided into eight narrow rooms, each lighted by a rectangular window about three feet in height and eighteen inches in width. Each of these windows was heavily barred.

Surrounding this massive structure was a wall twelve feet in height, surmounted by revolving rods studded with steel spikes, and pierced by a narrow gateway sufficiently wide to admit the passage of a handcart. This wall abutted on the barracks, and the space between the house and the wall, paved with stone flags, served as an exercising ground for the prisoners who were confined within. These were mostly men serving long sentences for insubordination and other serious offences against military and naval discipline.

Just inside the outer gateway was a small guardhouse in which were quartered the soldiers detained to act as warders. Here Hamerton was handed over to the jailers, and compelled to have a bath and don a suit of blue-and-yellow cloth that made him look like a football player. All his personal belongings—and they were few in number owing to his hurried departure from the yacht—were taken from him, with the exception of his watch. This done, he was escorted up the exterior staircase of the main prison and placed under lock and key in the room at the north-eastern angle of the building.

"Well," he soliloquized, "if this is to be my quarters for the next five years—though I don't think it will be, as long as there is a strong man at the head of the Foreign Office—I may as well make myself comfortable. It's rotten being without Detroit though. They might have left us together. Now, let us see how the land lies."

His first step was to attempt to drag the iron bed frame across the floor and place it under the window.

"Confound it!" he muttered. "They've bolted the thing to the floor. No matter, I'll see what I can do with the stool."

Altering the position of that article of furniture to the desired spot, the Sub found that he could just grasp the bars of the window. Then, at the expense of a pair of skinned knees, he succeeded in drawing himself up sufficiently to be able to look out.

The aspect was not satisfactory. The outlook was to the paved courtyard, a high blank wall of a large building on the other side of the street, the upper part of the church tower, and an expanse of cloudy sky.

"Well, if I am condemned as a spy I jolly well will be one," he continued. "There's not much to be seen from the window, so the sooner I see about getting out the better."

With that he descended from his uncomfortable position and began to pace the narrow limits of his cell. Round and round he went, almost aimlessly. It reminded him of an incident of his youth. He had caught a hedgehog, and, wishing to keep it as a pet, had enclosed a small extent of grass-covered ground with a circular fence of wire netting. As soon as the hedgehog had uncoiled itself it began to run round and round the fence, its nose continually poking at the meshes in the hope of finding an exit. The animal eventually made its escape by burrowing. Good heavens! The thought suddenly occurred to him: why could he not burrow his way out of his prison?

He sounded the walls. They seemed solid enough. The floor, too, looked of far too massive construction to be disturbed without the aid of proper tools. It was paved with stones averaging two feet square, set in hard cement. Every flag he tapped with his heel. The result was not encouraging. No hollow sound rewarded his efforts.

His usually deliberate manner seemed to have deserted him on the first day of his imprisonment. He felt consumed by an almost overwhelming desire to exercise all his energy at once, only prudence asserted itself.

"I'll lie low for a day or so," he resolved. "It will give me time to find out what routine is carried out. If they don't inspect the cells during the night I'll be able to work unmolested. If they do, by Jove! it will be a risky business."

Just then came the sound of men's footsteps along the stone passage. Planting his ear against the door Hamerton listened intently. Again he was unrewarded, for not a word was spoken by the men without. A door was unlocked, slammed, and locked again, and the sound of footsteps grew fainter and fainter.

A little later a couple of soldiers entered the Sub's cell. One of them remained just inside the threshold, the other placed an earthenware plate containing a piece of black bread and a morsel of cheese upon the bed and a jug of water on the floor.

"Look here," said Hamerton, looking disdainfully at the frugal repast and addressing the men in their own language; "is this the best I am to have?"

"I've money. There's a fairly large sum belonging to me on the yacht. Can't I have food sent in to me from outside?"

The men backed out, relocked the door, and left Hamerton to his meditations and his supper. He ate all the food that had been provided for him, and drank about half the contents of the pitcher. The rest he saved to quench his thirst during the long hours of the night, for he had a foreboding that he would obtain very little sleep during the hours of darkness.

He half counted upon the return of the jailer with writing materials, but no one came. He must exercise his patience and wait. "If I get hold of my spare cash within a week I shall be lucky," thought he.

The increasing gloom of the cell warned him of the approach of night. While the light remained he arranged the coarse blankets of his bed. The supper plate he placed against the door, so that upon anyone attempting to enter, the clatter would warn him. Directly it became night the searchlights along the edge of the cliff flashed incessantly.

Partially divesting himself of his clothing, Hamerton lay down upon the uncomfortable bed. There he remained without any desire to sleep. His mind was revolving the events of the day. His unjust trial, the separation from his companion, rankled within his breast. He wondered how Von Wittelsbach, with all his cunning, would continue to conceal the identity of his victims. What were the secrets of the forbidden land that were so jealously guarded?

The tapping sound was resumed. The noise seemed to come from the adjoining room.

"Great Scott! Is it someone trying to call me up in Morse?" he asked. "It may be Detroit."

Springing out of bed he groped for the plate that he had placed against the door. "Tap, tap—tap—tap, tap—tap," he signalled, the double sounds corresponding with the "dashes" of the Morse code.

For the best part of an hour the friends conversed at the rate of about six words a minute. It was slow work, but the fact of being able to communicate at all was a source of mutual satisfaction. Caution prevented them from discussing any probability of escape, for should their jailers hear and understand the messages that passed between the prisoners it would be almost a certainty that one of them would be moved to a more remote part of the building.

At intervals during the night communication was re-established. Dawn found Hamerton weary-eyed and pale. He had not slept a wink.

At seven the warders appeared, bringing the Sub's breakfast. This consisted of a kind of coarse porridge and a slice of rye bread.

Without waiting to be questioned further the men took the plate that they had left overnight and went out.

"That fellow won't break his jaw through too much talking," commented the Sub. "One blessing, they didn't trouble us during the night. I'll start tunnelling this very evening."

An hour later the door was opened again. This time there were two different soldiers. One of them carried a broom, which he gave to Hamerton and signed that he should clean out his cell.

"Ja," came the reply in a tone meant to imply that the information was not of the slightest interest to the taciturn fellow.

They waited till Hamerton had completed his task. The broom and the breakfast utensils were placed outside the cell, and the Sub was ordered to follow his jailers.

However, such was not the case. Hamerton was conducted into the exercise yard and allowed to walk up and down for the space of nearly an hour. This over, he was taken back to his cell and locked in.

At tea-time he deliberately dropped the earthenware plate upon the stone floor, and selecting a pointed fragment hid it under his bed. When the jailers returned, one of them carefully gathered up the remaining fragments, received the Sub's explanations with the perpetual "Ja", and went out.

The Sub reckoned that he would be uninterrupted until seven o'clock; he had nearly three hours to conduct operations. Selecting a slab of stone in a dark corner of his cell adjoining that tenanted by Detroit, he began to attack the cement. It was almost as hard as iron. The fragment of earthenware was a most unsatisfactory tool, for at the end of three hours he had made only a deep scratch in the cement, and had chafed his hands till they were covered with blisters. Yet so intent had he been on his stupendous task that, until he "knocked off", he was unaware of the damage he had wrought to his hands. That night he spent in alternately communicating with Detroit and attacking the stubborn cement, snatching a few hours' sleep towards morning.

Exercise time came round. On the previous day he had kept his eyes well about him, studying the relative position of the windows and the ground, and mentally measuring the height of the enclosing walls. This time he paced up and down, never walking over the same track twice. He kept his eyes on the ground, hoping to find some piece of metal which he could press into his service. With his eyelids half-closed his demeanour excited no suspicion amongst the soldiers detailed to keep him under observation.

Presently he caught sight of what appeared to be a rusty nail, almost buried in the narrow strip of cultivated ground bordering one side of the paved courtyard.

Thrice he passed it before he purposely tripped over a conveniently uneven stone, and fell full length upon the ground, his hands sprawling in a seemingly vain endeavour to save himself. Even his wooden-faced guards smiled at the sight of the Englishman kissing the ground. But when Hamerton regained his feet a piece of steel, nearly seven inches in length, was reposing within his sleeve.

As soon as he was relocked in his cell he eagerly examined his prize. It was a portion of a steel prong, doubtless snapped off by a sudden contact with the stone wall. It was rusty, but the rust had not eaten deeply into the metal. It rang truly when dropped upon the floor. Hamerton would not have parted with it under present conditions for a hundred pounds.

The next thing to be done was to find something suitable for a handle. Experience had already taught him the need for a protection for the hands.

Upturning the stool, he examined the joints of one of the legs. It was not screwed, but merely jammed into the thick wooden seat. Before wrenching it off he bored a hole into one end with the pointed part of the steel, enlarging the hole sufficiently to be able to insert the blunted end. This took him nearly two hours' continuous work, but at the finish he found himself in possession of quite a sharp and efficient tool.

Well before the time of his jailers' visit he withdrew the steel and hid it in the under side of the bed, replaced the leg of the stool, and resigned himself to a period of inaction.

As soon as it became dark the searchlights were switched on. Hamerton could see the giant beams travel slowly across the sky, although most of the searchlights were trained to sweep the surface of the sea. At frequent intervals the bark of quick-firers shook the solid building. A night attack, one of the frequent attempts upon Heligoland by the Borkum flotilla of destroyers, was in progress. Similar manoeuvres were of almost nightly occurrence.

The detonations of the ordnance were of immense service to Hamerton. He could begin operations with less chance of being detected, for the rasping of the steel point against the cement was inaudible during the firing.

Nevertheless, it was slow work chipping out minute particles of the stoutly resisting substance. Frequently he paused to gather up a handful of the debris and hurl it out of the window. In two hours he had cut out the cement to a depth of two inches round the fairly large slab which he had fruitlessly attacked with the fragment of the broken earthenware plate.

Shortly after eleven o'clock the firing suddenly ceased, although the searchlights were still flashing across the sky. There was now more need for caution. The Sub stuck grimly to his task, pouring water into the little rectangular trench in order to deaden the sound of the steel. Several times he had to "knock off" in order to reply to a signalled message from Detroit.

"No, not in the sense you mean," replied the Sub. He would dearly have liked to inform the American of the work he was undertaking, but, fearing that the conversation was possibly being listened to by a third person, he refrained. "I'm dead tired," he added.

Hamerton looked at his bruised and blistered hands and smiled grimly. The irony of the American's question tickled him.

Far into the night he toiled. The stone showed no sign of loosening in its bed. Again and again he ground the edge of the piece of steel and attacked the stubborn cement, which seemed to possess the toughness of iron.

"I'll carry on for another quarter of an hour," he said to himself, as he wiped the perspiration from his forehead. "I wonder what's——"

The rasping of a key being inserted into the lock of the door caused him to start to his feet. There was no time to replace the leg of the stool, which was lying on its side. Thrusting the precious implement under the mattress, Hamerton leapt into the bed, drew the blanket well over his face, and simulated a snore.

The door was thrown open. There was a pause. It seemed to the Sub like the slow passing of at least half an hour. In his heated imagination he fancied the intruder had discovered the signs of his handiwork. He could discern through his almost closed eyelids the glimmer of a lantern upon the whitewashed stone walls of the cell.

He attempted another snore. It was a dismal failure; it seemed to him more like a pig's grunt than anything else he could think of. Then the light vanished, the door was closed with less noise than it had been opened with, and once more he was alone.

For nearly ten minutes Hamerton lay still. He was half-afraid that the suspicions of his visitor had been aroused, and that the man had gone away to bring the guard and make a thorough examination of the place. At length, pulling himself together, the Sub got out of bed, removed the steel from its handle, and replaced the leg of the stool. The dust that he had not thrown away he mixed with grease from the remains of his supper, and worked it into the crevices surrounding the stone that he was determined to remove.

This done, he threw himself upon his bed, and, being thoroughly tired out, was soon in a sound, dreamless sleep.

CHAPTER XI

A Night of Toil

Four days passed. Hamerton's jailers, in spite of the monotonous "Ja's", had neither brought the promised writing materials nor taken any steps to help the prisoner to recover his money.

The work of loosening the refractory stone made steady progress. Once or twice the Sub fancied that it was shaking in its hard setting. He even went so far as to break off the tip of his steel instrument in a vain attempt to prise up the slab. The experiment was almost a disastrous one, for Hamerton had to regrind the steel ere he could start afresh. Luckily it was still long enough for the purpose, and also more rigid, while he had still the broken part as a supplementary tool.

"Hans," remarked Hamerton to one of the jailers in quite a casual tone, when the fellow brought a basin of soup to the prisoner, "could you let me have a little pepper?"

The man eyed Hamerton suspiciously; then, instead of the monotonous "Ja ", he demanded:

"What for? I suppose you would like to have some? It would come in useful to throw in my eyes, and you would try to break out of prison, eh?"

"No," replied the Sub coolly. "I can assure you that I would not use it for that purpose. I have a cold in my head."

"It's not worth that. I have always found pepper an excellent remedy when nothing better is to hand. Can't you get me a little?"

"Here you are, Englishman," he said, handing Hamerton a small paper parcel. "It's strong enough to blow your head off."

Directly the man went out Hamerton placed the packet of pepper in the only pocket of his coat, in which there was already a couple of handkerchiefs and his watch.

"I didn't think I should obtain the pepper so easily," he soliloquized. "It will come in very handy before many days are past."

Hamerton made a late start that evening. Detroit was in a very communicative mood, tapping out messages with tremendous zeal, till his friend had to caution him not to make so much noise, through fear of being overheard.

It was just twelve when Hamerton, using the steel as a lever, found to his great delight that the stone was actually loose. For the next half-hour he worked like one possessed, with the result that the slab was displaced. Half-dreading the outcome of his investigations, Hamerton groped cautiously with his hand into the deep cavity. Almost at arm's length his fingers touched a mass of rubble. The floor was hollow.

Now, for the first time since his incarceration, the Sub wedged the door of his cell by means of the stool. Thus he was fairly safe from interruption, and in the event of a nightly visitation he might be able to replace the stone and hide the traces of his handiwork before admitting his jailers.

This done, he attacked the slab adjoining the hole in the floor. By dint of much heaving he succeeded in displacing it without having recourse to the tedious process of chiselling out the cement.

"I wish I had a box of matches," he muttered. "Only a mole could find its way about in that hole. Well, here goes!"

So saying, he lowered himself into the pit, so black that by contrast his cell was fairly illuminated, for the searchlights were constantly flashing skywards.

Between the under side of the stone floor and the rubble on which he stood was a space of about eighteen inches in height. It was like sitting on the summit of a mound, for the surface descended on all sides. Hamerton was standing on the crown of one of the vaulted arches of the store under the prison cells. During his exercise hour in the courtyard he had made the discovery that the room on the ground floor was vaulted.

"Easy ahead!" he muttered between his closed teeth, for the dust rose in clouds in the confined space. Before he had crawled very far the height increased sufficiently for him to be able to kneel upright. Then his hands came in contact with a wall—the division between his cell and that occupied by the American.

"Rough luck!" he ejaculated. "More miniature pick-and-shovel work, I suppose. Ah, there's Detroit tapping again! Sorry I can't attend to you, old man."

Groping with his left hand Hamerton followed the course of the parting wall, hoping that he might find an opening into the space beneath Detroit's cell. His hopes were realized, for almost at the junction with the outer wall of the building was a gap in the stonework.

"It will be a tight squeeze, by Jove!" he ejaculated. "I'll risk it; but what a mess I'll be in!"

He had not before taken into consideration the fact that the state of his clothes would "give the show away" to his jailers. Retracing his steps he regained his cell, and promptly stripped off his hideous prison garb, shook out the dust, and laid the garment on the bed.

Once more he dropped into the hole, and with more confidence crawled to the corner of the space where he had located a means of communication with the corresponding cavity on the other side of the dividing wall.

It was a dangerous performance wriggling through the narrow aperture. More than once Hamerton had to stop through sheer exhaustion. The rough stonework grazed his ribs and lacerated his elbows and thighs. It seemed as if he stood a great chance of becoming jammed, for, having succeeded in forcing his shoulders through, his hips obstinately refused to scrape between the sides of the opening. To add to his discomfort, the air was far from pure, and he was seized by an attack of dizziness.

Temporarily panic-stricken, he struggled furiously and contrived to back out of his dangerous predicament.

"It will mean enlarging that hole," he thought. "I've done enough for the time being. To-morrow night I'll have another shot at it."

With this resolution he returned to his cell, washed off the dirt, and turned in, glad to rest the bruised angularities of his aching body.

Presently he began to ponder over the difficulties that had beset him. "Either I'll have to make that hole larger or I'll have to reduce my fat," he said to himself, with a laugh. "Talk about a square peg in a round hole, or a round peg in a square hole. By Jove! I'm an ass. The hole is square right enough, but my midship section isn't round—it's oval. If I had only kept my hips in two opposite corners instead of trying to squeeze through on my stomach I could have done it hands down. I wonder what the time is?"

Even as he looked a brilliant beam of light flashed straight in through the window. It was a quarter to one. For a few seconds only the searchlight rays played upon the building; then all was darkness, rendered the more opaque by reason of the sudden change.

"A searchlight from an airship," exclaimed the Sub. He knew perfectly well that since from his window he could see nothing of the searchlight apparatus placed on the fortifications, it was conversely impossible for one of those searchlights to throw a direct beam through the window of his cell.

In a trice he was out of bed. Propping the partially dismembered stool against the wall, he climbed up to the window and looked out. He was just in time to see a large Zeppelin in the act of descending somewhere to the left of his prison. By the arrangement of the cars he knew that it was not the same craft that he had seen recharging her petrol tanks on the morning of his arrest.

"I wonder whether they are stationed here?" he asked himself. "An airship of that size must need an enormous shed, yet I'll swear I never saw one when I was being taken ashore. And they would never risk mooring a lubberly craft like that in the open."

As there was nothing more to be seen, the Sub clambered down from his insecure perch and prepared once more to turn in. Suddenly he felt inclined to put his theory to the test. It was not yet one o'clock, four precious hours yet remained ere dawn. He would make another attempt to squeeze through that baffling hole in the wall.

This time he succeeded with comparative ease, although his bruised hips gave him a bad time of it during the operation. In his sense of elation pain and discomfort were forgotten, for he was now underneath the cell occupied by his comrade, with only six inches of stone floor to separate them.

It puzzled Hamerton considerably to know how the stone flags were supported, since there was a cavity underneath the floor, but now he made a discovery that he had hitherto overlooked. The floor had been constructed at a fairly recent date, and was supported by slight iron girders, spaced about eighteen inches apart, which were in turn supported by small brick piers rising from the upper side of the vaulting. Fortunately the Sub had by chance decided to remove a stone that was only partly resting on a girder and held in position by a wedge-shaped stone—the second one that he had removed.

"It's about time I gave Detroit a hint," he thought. "I'll tap out a message as lightly as possible, in case the sound travels to another part of the building."

"Am crawling under the floor of your cell," he announced. "Will try and join you either to-night or to-morrow. Have you anything you can use to help shift one of the stones?"

Considering Hamerton had been "hustling" like a nigger for hours this request struck him as being a cool one; but, guessing rightly that it was owing solely to Detroit's enthusiasm at the prospect of being joined by his chum, the Sub began to tackle the new phase of his arduous task.

Feeling for a stone that projected farther than the rest, Hamerton began to tug at it with his hands. It was seemingly immovable. He realized that the only way to shift it was to dig out the cement, as he had done in the case of the one in his cell. But there was a difference. He had to be on his back; the dust fell upon him, getting into his eyes, nose, and mouth, and causing him acute discomfort. Only by his sense of touch could he determine whether he was attacking the cement or merely the hard stone.

At length his physical strength began to fail; his arms refused to obey the dictates of his active mind. Reluctantly he abandoned his task for that night and painfully crawled back to his bed. It was then a quarter-past three. For close on two hours and a half he had toiled under adverse conditions, yet the result of his labours was satisfactory. He had almost established a direct communication with his friend without having recourse only to conversation in Morse.

With this solace to act as balm to his wearied body the Sub was soon fast asleep, nor did he awake till his jailers appeared with his breakfast.

CHAPTER XII

Investigations

On the following night, as soon as the bugles sounded "Lights out", Hamerton returned to his labours. Barricading the door and wrenching up the loosened slabs of stone, he descended beneath the floor, wriggled through the hole in the parting wall with comparative ease, and with renewed energy began to prise away at the stubborn cement. At about every quarter of an hour he would seize the projecting stone and shake it violently. Perhaps he had become hardened to the work, for he imagined that the cement was not so hard or tenacious as it had been when he began operations. "The cement is cracking," signalled Detroit, who for the last two hours had been lying at full length on the floor feeling for the first decisive tremor of the paving stone.

Then Hamerton had an inspiration. He knew that the stone was wedge-shaped; perhaps by pressing upwards against it he might force it out of position.

Crouching immediately under the projecting piece of masonry, he applied his shoulder to the base of the wedge and exerted all his strength.

For a few seconds there appeared to be no result, then, almost without warning, the stone gave quite a couple of inches, till it was flush with the adjoining slabs.

Detroit felt it rise. Desperately he wrenched at it with his bare hands. Hamerton, rolling over on his back, pushed as hard as he could with his foot. The next instant he felt the American's sinewy fingers grasping him by his toes.

"Guess I don't care, so long as I've got hold of some part of you," was the glad response. "Let's have your hand, then."

It did not take very long for the hole to be enlarged sufficiently to allow Hamerton to enter the American's cell. By a sheer piece of luck the aperture bore the same relative position to the floor as did the one in the adjoining room. It was almost in the corner, where, in the daytime, by contrast with the light filtering through the window, it was almost dark.

For some considerable time the reunited comrades whispered in tense, excited tones, their conversation being the outcome of joy rather than the discussion of a definite plan of action. But by degrees they grew calmer, and Detroit asked what the next move was to be.

"Get out of this show as soon as possible," announced Hamerton with determination.

"And then? We are not paladins; we cannot hope to overpower the whole garrison. There are sentries at every few yards; every boat is guarded. We will have to remain hidden on this little rock till hunger compels us to give ourselves up."

"We'll risk that. In almost every enterprise there is an element of chance that oft leads to success. Once we break out of this place we'll have a good look round. They've condemned me as a spy, and, by Jove, I'll do a little espionage!"

"And I'll have a shot at it," added Detroit. "Who knows but that some day the United States Navy may be glad of certain information concerning this island."

"'Of course we may stumble upon a boat," continued Hamerton. "In that case we'll appropriate her without the slightest compunction, get under way, and trust to luck to be picked up by a passing steamer. A few miles either to the north or south, and we'll be right in the regular steamer tracks across the North Sea."

"But the searchlights?" objected Detroit. He was game enough for any enterprise, but with natural caution he preferred to weigh up the risks.

"If we start just before dawn we need not worry about searchlights. I noticed they ceased operations at 4 a.m. the other day. We ought to be able to put five miles between us and the rock before it is light enough for them to spot us."

"All right, then!" assented the American. "But we're not out of the wood yet. What's the next performance?"

"I'm off back to my cell. Take care to replace the stone carefully and fill up the joints with dust. I'll leave you this little tool—I can't let you have the handle, for, as you see, it's the leg of a stool. If you feel particularly energetic, old man, you might start at the sockets of the window bars. You'll have to be very cautious. Do they march you out for exercise?"

"I have an hour of it also. Thus I was able to take stock of the building. Your window is directly above a flight of steps; mine is some distance clear of it. Consequently your window is the more convenient one for us to tackle."

The next day passed in a most tedious fashion. Hamerton was on thorns more than once, for in his heated imagination he fancied that his jailers purposely prolonged their visits to his cell.

"To-morrow," announced Hans, "you will roll up your blankets. Clean ones will be served out. You will also have to scrub your floor, because the governor of the prison and the medical officers are going to make an inspection."

This was disconcerting news. It was a case of to-night or not at all, for it was quite evident that should the two comrades not succeed in making their escape before the morrow, the visiting authorities would be almost certain to discover the displaced stones in the floor.

Accordingly the Sub continued his preparations. In spite of his hearty appetite he set aside one-half of his day's rations, since it was doubtful whether he would be able to obtain food outside.

Evening came with a furious easterly gale. The wind howled, heavy drops of rain fell in torrents and beat in at the open window, for during the summer months the glass was regularly removed from all the prison cells.

Hamerton welcomed the storm. It was an asset in their favour, although for the time being it was useless to expect to be able to get away from the island in a boat.

"Guess I've just about shifted those bars," was the American's reply. "The cement was rotten."

"Rather," agreed Detroit; "besides, we haven't made the ropes yet. Bear a hand with this blanket; we'll soon manage that, I think."

"Pretty tough stuff," commented Hamerton, as the property of the German Government was remorselessly torn into strips. "All the same I'd rather have a good piece of manila or three-strand hawserlaid tarred rope. Even a sheet would make a better rope."

In spite of his objections Hamerton tackled the task with energy, and as a result of their joint labours the comrades had the satisfaction of being in possession of thirty feet of apparently serviceable rope.

Five minutes sufficed to complete the removal of the bars. Hamerton, having made one end of the rope fast to the bed frame, clambered up the ledge, and listened intently. Not a sound was audible above the howling of the wind and the hissing of the rain. The Heligoland searchlights were not running, but from Sandinsel four powerful beams were swaying across the cloudy sky like gigantic inverted pendulums.

Detroit handed up the coiled rope. The Sub was about to drop it into the black vault beneath him, when he saw the glimmer of a lantern on the rainswept pavement below. Crouching on his narrow perch the Sub waited. The rays of the lantern reflected in the puddles of the courtyard; it glinted upon naked steel and upon the brass helmets of a file of soldiers.

Straight towards the staircase came the men. The Sub felt his head throbbing violently. They were more than likely sent to escort the alleged spies to another place of detention.

With a dull crash the butts of a dozen rifles struck the stone pavement as the men halted and grounded arms. With bent shoulders, in a vain attempt to shelter themselves from the rain, the soldiers waited while the sergeant, lantern in hand, ascended the steps, followed by an enormous bloodhound.

Hamerton durst not crane his neck to see what went on almost underneath the window. He could distinguish Hans's voice replying to the sergeant's questions, but the din of the storm prevented the listener from understanding the nature of the conversation.

Then, after what seemed to be an age of terrible suspense, the Sub saw the sergeant return to his men. The soldiers recovered their arms, faced about, and marched towards the outer gateway. The light vanished, and the tramp of their feet was soon lost in the moaning of the wind.

Hamerton waited no longer; at any moment the jailers might intrude. Noiselessly he allowed the coil of blanket-rope to drop into space, then, grasping one of the bars which still remained, he assisted Detroit to clamber up beside him.

"You go first," he whispered. "You're lighter than I am. If the rope should break when I descend, don't wait, but clear out."

"I won't," replied Detroit. "We'll stand by each other at all costs. Well, here goes!"

The next moment he was lost to sight. Hamerton could feel the rope stretching and jerking under the strain of the descending man's weight. Presently the tension ceased. The American had reached the steps beneath the window.

Without hesitation Hamerton followed. He realized that should the soft fabric give way a fall of about ten feet, followed by a headlong tumble down the stone steps, would be the inevitable result, and to a man weighing close on fifteen stone that was far from pleasant to contemplate.

But the rope stood the strain, and with a muffled exclamation of thankfulness Hamerton felt his feet touched one of the stone steps.

"Heave away!" he whispered, placing the rope in Detroit's hands. Both men pulled their hardest. The blanket rope parted, leaving about ten feet of it in their possession. Then the American saw his companion do a strange act. Hamerton drew a packet from his pocket, and, holding his nose tightly with his left hand, scattered something on the ground. It was as much as Detroit could do to restrain his curiosity.

The outer wall with its array of spikes presented little difficulty. Detroit clambered on to Hamerton's shoulder, grasped one of the revolving rods, and passed the bight of the rope around it. By this means he was able to draw himself up and crouch astride of the obstacle until Hamerton swarmed up beside him. The drop on the other side was a more nerve-racking ordeal, for neither of the fugitives knew what was beneath them. Fortunately it was a vegetable garden belonging to one of the jailers, and the soft earth effectually neutralized the otherwise nasty jar of a twelve-foot drop.

Once again Hamerton stopped to scatter something from the packet. Detroit recognized it now. It was pepper. It nearly made him sneeze. Then he realized what his companion was about. Hamerton meant to baffle the bloodhounds that were kept on the island for the purpose of assisting the sentries in arresting all suspicious characters and maintaining the jealously guarded secrets of the island fortress.

"Rather not," replied the Sub. "It's too well guarded. We'll strike inland and make good use of our liberty until the alarm is raised."

Guided by the chain of searchlights, which were now in full swing, Hamerton and his companion set off in a north-westerly direction. Once clear of the buildings they felt the force of the wind, which had now backed to the north-west. It was a struggle for them to keep their feet. Every now and again a vicious blast would bring them up "all standing", as Hamerton would have described it in naval parlance. As for the rain, it was too torrential to aid their flight, for at any moment they might blunder upon the sentries, since they could see barely twenty yards ahead, and that only very indistinctly.

Away on the right a wind motor, perched on a cast-iron tower, added to the din. It was one of several used for generating electric current for the searchlights, and could, if necessary, be lowered into a concrete-lined pit, so as to be out of reach of a hostile fire.

Hamerton pushed forward, counting the number of the steps he took. At the sixty-first he stopped abruptly and threw himself flat upon the grass, an example that Detroit promptly imitated.

Just in front of them was a high barbed-wire fence. On the furthermost side a sentry was standing, his hands resting on the muzzle of his rifle and his head bowed till the brim of his flat-topped cap touched his fixed bayonet.

For nearly five minutes the man remained in this position, though fortunately his face was turned slightly away from the two recumbent figures on the ground. Then, sloping his rifle, the sentry faced about and stolidly marched away, following the direction of the fence.

"There must be some object in posting a sentry so far from the road and away from the cliff," thought Hamerton. "I'll investigate."

With that he rose to his feet, grasped the lowermost of the barbed wires, and held it up as high as the tension would allow. The quick-witted American understood, and, throwing himself flat on the ground, crawled under the formidable fence. In turn he performed a like service for the Sub, and the two adventurers found themselves within an entanglement out of which they could not easily escape should their presence be detected by any of the sentries.

While negotiating the fence Hamerton noticed one remarkable thing: the standards supporting the spiked wires were set in hinged sockets. Also, about five feet from the fence lay several half-rounded pieces of metal, each about ten feet in length.

"They are in the habit of lowering the fence for something," said the Sub to himself. "These sections are to place over the wire when it is lying on the ground. Seems as if they take rather fragile objects into the enclosure; which, I wonder?"

The something proved to be the stone facing of a steep incline cut into the earth. The investigators had the choice of two routes, either to bear away to the left and follow the natural terrain, or take the right-hand direction and descend the incline. They chose the latter.

The shelving ground was slippery with rain. Close to the concrete wall was a small channel through which the surface water poured in a miniature torrent. Extreme caution was necessary, since at any moment the two comrades might find themselves precipitated over the edge of a pitfall.

"Come this way," said Hamerton in a low voice. "I want to find out the width of this incline." And setting off at right angles to his previous direction he began to measure the distance. At the eightieth pace—equal to one hundred and twenty feet—the adventurers found themselves confronted by a wall similar to the one on the other side of the incline. They had stumbled upon a broad way, leading they knew not whither or for what purpose.

"Better not," objected Detroit. "If there are any people about they will naturally choose the lee side of this wall. We can't get much wetter, and we stand a better chance over there."

"Right!" assented the Sub. He was not above paying good heed to the American's sagacity.

Accordingly they retraced their steps to the left wall of the incline and then resumed the downward direction. Higher and higher grew the wall, till it was lost to sight in the darkness. It seemed as if they were descending into the bowels of the earth. Presently both men involuntarily paused. Through the rain-laden atmosphere came a red glare. It only lasted a few seconds and then disappeared.

"A furnace," whispered Hamerton. "Luckily it was not on our side. Ha! what's that?" His feet came into contact with the metal rail of a narrow-gauge tram line, emerging from a cave-like chamber in the wall and running athwart the incline. Further investigations revealed the presence of a siding on which were several trucks laden with coal. The trucks had been filled by means of a number of shoots. Close by, under a lean-to shed, were nearly a hundred barrels, some empty and lying in disorder, and others filled and stacked in tiers.

Even as Hamerton and his companion were making this discovery an arc lamp above their heads was switched on, flooding the ground with its powerful light. Simultaneously the door of the subterranean store was thrown open and a row of trollies, propelled by an electric motor, emerged from a tunnel that had hitherto escaped their notice.

To stay where they were meant detection. Flight was equally dangerous, since they would have to cross the brilliantly lighted ground. By a common impulse the Sub and his comrade vaulted into two upturned barrels.

They were just in time. The trucks came to a standstill almost opposite their place of concealment, and a squad of men, dressed in engineers' uniform, began to fill the tilt-wagons. This they did by the aid of small electric cranes. Rapidly the heads of the requisite number of barrels were stove in, and the casks, raised by means of cliphooks attached to the wire ropes of the cranes, were emptied into the waiting trucks.

Hamerton could overhear the sergeant in charge of the party grumbling about the weather.

"Be careful, men," he cautioned; "if the moisture gets to the alum there will be a row. Now, sharp with the trucks, or Herr Captain will be in a rage. 'Z 21' must be filled before daylight. Hurry up, I say."

Away rumbled the trucks, the men either clambering upon them or returning to the subterranean room from which they had emerged. The arc lamp was switched off and all was dark once more.

Then the blaze of red light reappeared. Hamerton understood. This was the hydrogen factory where the gas for filling the Zeppelins was manufactured. He remembered that woollen or linen fabrics saturated in a solution of alum become practically non-inflammable. There were the men shovelling lumps of alum into one of the retorts.

"I have it," he muttered triumphantly. "They have discovered a process of making hydrogen practically non-explosive. By Jove! I wish I could wrench the secret from them. However, it's a step in the right direction."

Noiselessly the pair emerged from their place of concealment. Detroit was curious to know the nature of the conversation, but for the present it was extremely hazardous to speak. He had, however, made the discovery of the former contents of the barrel in which he was hidden, for happening to put his finger to his lips the unpleasant taste of alum asserted itself.

Stepping cautiously over the tram lines, since one of them might be a "live rail", Hamerton and Detroit resumed their down-grade journey till they had traversed nearly a quarter of a mile of the incline.

"I believe we've tumbled upon the approach to a submarine tunnel to Sandinsel," whispered Detroit.

"Much too wide for that," replied the Sub, "unless, of course, there is a subsidiary tunnel. But, look, we are getting to the end. There's rock ahead of us."

The incline terminated in a large circular basin roughly two hundred yards in diameter. Opening out of it were three lofty artificial caves, hewn out of the sandstone. This much Hamerton was able to observe in a momentary burst of starlight through a rift in the swiftly-moving clouds.

"Come on," he said. "We're in luck's way. There's no one about. Follow the cliff; I'm curious to see what is in these caves."

The first cavern was apparently empty. The floor was paved with slabs of cement, the walls were of glared brick. Close to the mouth was a little hut, the door of which was locked; but judging by the number of insulated wires running from it the Sub concluded it was the operating station for lighting the vast recess.

The second cave, its entrance being almost at an angle of ninety degrees with the first, was tenanted. Both men recognized in the snub-nosed object projecting far above their heads the bow of a military Zeppelin.

Hamerton could have danced with sheer delight. He had discovered what was supposed to be the shell-proof lair of three powerful airships. Deep in the bowels of the earth they were immune from hostile shell. A high-angled fire might result in a projectile dropping into the vast circular pit, but the possibility of the aircraft being damaged by fragments of shells was guarded against by the provision of massive steel doors sliding on rollers.

Evidently the Zeppelins were being made ready for a flight, for the doors were wide open. In the third cavern lights burned at the farthermost end, and a party of officers and men were busily engaged in overhauling the after-car.

"Suppose we must," replied Hamerton reluctantly. "It must be close on dawn, and we'll have to find a place to stow ourselves away."

"That airship facing the incline can come out of its dogbox all right, but I don't see how the others can be turned. There can't be more than a few feet between their extremities and the cliff when they are hauled out."

"I wish the whole crowd of them would meet with no end of damage," said the Sub vengefully. "But come on, we mustn't hang about here till morning. I heard those fellows say that one of the airships was to be made ready by daybreak."

"One minute; I guess I'd like to look around over there," said Detroit, pointing to the centre of the circular bed of the pit. So saying, he made his way cautiously from the shelter of the cliff, and Hamerton, guessing that his comrade was on the verge of a new discovery, followed.

For the first ten yards the floor was literally covered with a network of tram lines. There were treble parallel tracks, points, and sidings galore. It reminded the Sub of a miniature Clapham junction.

"I thought so," he announced. "We've hit the edge of a gigantic turntable. This is how they slew round their blessed Zeppelins."

The floor of the turntable was almost as smooth and level as a billiard table. There was not a single projection that would form the slightest hindrance to its intended burden. Almost in the centre were a couple of flat trapdoors for the purpose of gaining access to the machinery underneath, but the actual moving of the turntable was controlled by means of electric switches from a cabin close to the wall of the basin.

"Say, why not hide down there?" suggested Detroit, pointing to one of the trapdoors.

"Good idea!" assented Hamerton. "I don't suppose anyone goes down except to oil the machinery. The place looks large enough to hide a dozen people quite comfortably. Besides, we might be able to see something by daylight. Give me a hand with this lid."

Luckily the traphatch was not locked. The authorities regarded themselves as being immune from the inquisitiveness of intruders and the mischievousness of small boys.

Detroit descended first by means of a vertical iron ladder. Hamerton followed, and was in the act of reclosing the lid of the aperture when the whole of the Zeppelin sheds and approaches were illuminated by arc lamps fixed from brackets to the side of the cliff.

And right in the centre of that blaze of light, his head and shoulders showing conspicuously above the level of the turntable, Hamerton remained as if rooted to the spot. The sudden glare temporarily blinded him. He felt incapable of moving hand or foot.

CHAPTER XIII

An Experiment with a Zeppelin

The American's words roused Hamerton to action. Quickly he descended below the level of the floor of the turntable, the flap fell with a dull thud, and the two fugitives found themselves in darkness, save for a faint circle of light where the exterior glare filtered through the narrow space between the round platform and the edge of the pit in which it stood.

Then came the tramp of many feet. Not knowing whether they had been "spotted" by a keen-eyed sentry, Hamerton and his comrade remained on the thorns of expectancy. Alternate hopes and fears flashed across their minds in quick succession. Detroit was mentally bemoaning the rashness that prompted Hamerton to suggest the exploration of the aircrafts' subterranean shelter instead of making for the base of the cliffs; while the latter regretted that he had not been able to continue his nocturnal tour of investigation.

Yet, although men were running hither and thither, none came across the floor of the turntable. Trucks were rumbling along the tram lines, men were shouting in guttural tones, electric motors were whizzing and buzzing. The place, hitherto practically deserted, resembled a gigantic beehive.

"They are not looking for us," whispered the Sub. "They are evidently getting one of the Zeppelins ready for a flight. I hope we won't be disturbed. We may as well have a tour round our limited quarters, to make ourselves acquainted with our hiding place."

"Trust me for that," rejoined Hamerton, "We don't want to electrocute ourselves, or start the turntable spinning round at the rate of knots."

"Like a new form of joy-wheel," added the American. "It would be a bit of a joke to see the soldiers attempting to reach the traphatch with the platform spinning round at twenty miles an hour."

Their eyes were now getting accustomed to the gloom, for there was a fair amount of reflected light that at first was almost unnoticeable after the powerful glare without.

The place of refuge was certainly expansive, but much of the space was taken up with complicated machinery. The turntable itself worked on steel rollers set in a "race", the upper bearing surface consisting of steel skeleton trestles, which in turn supported the revolving platform. Between the latter and the edge of the circular concrete wall was a width of less than eight inches, insufficient to allow a man to crawl through. The only means of gaining the machinery chamber was by the two trapdoors.

"No use," replied Hamerton. "It would only arouse suspicion. Then we should either be starved out or run the risk of being potted, for the floor is not proof against rifle fire. No, the best thing we can do is to keep quiet. Should anyone come we must endeavour to dodge behind some of this gear."

"Now you mention it I begin to have a sinking sensation: a kind of famine and hunger strike rolled into one. But we can't go too strong in the provision line."

Six half-slices of rye bread, two small pieces of cold meat, and about a pound of fish formed the sum total of the commissariat, barely sufficient, even with stringent economy, to last over twenty-four hours.

The food, after reposing in their pockets, was not pleasing to the eye, but adverse circumstances settled all qualms. Both men ate with avidity, though sparingly.

At length daylight gained the mastery over artificial lighting, and the arc lamps were extinguished. With the morning the rain ceased and the wind dropped.

Peering through the gap between the turntable and the encircling wall, Hamerton could see the sun shining upon the upper portion of the red sandstone cliffs that enclosed the vast artificial basin. His field of vision was limited, but he was able to come to the conclusion that the floor of the airship sheds was nearly two hundred feet below the surface of the tableland that comprised the major part of the island.

Between each pair of caverns constructed for the accommodation of the Zeppelins was an iron ladder running perpendicularly up the sheer wall of sandstone. These were connected by an open lattice platform just above the crown of the arch formed by the caves, and were evidently for the purpose of facilitating the movements of the airships when entering or leaving their bases. Curiously enough, both Hamerton and Detroit had previously failed to notice these ladders when making a circuit of the basin.

"They are naval airships," announced the Sub, for men were swarming up and down the ladders with a seeming recklessness that only seaman dare show, and they were wearing the uniforms of the German Imperial Navy.

"Here she comes," said Detroit, as the huge bulk of a Zeppelin emerged slowly yet steadily from its resting place.

"What a superb target!" commented the Sub. "A dose of shrapnel would knock the whole concern to smithereens, while one of our seaplanes with a one-pounder automatic gun would make rings round her."

"I don't know so much about that," said Detroit. "Just look at the aluminium body just abaft the 'midship car. It's been holed at one time, and they've put a patch on it."

Over the heads of the two watchers passed the unwieldy craft. Now they could hear the jar of the framework as it settled on the turntable. Then, with hardly a sound and barely a tremor, the platform began to move until the bows of the Zeppelin pointed in the direction of the great incline. The six propellers began to revolve, and the airship, gathering way, rose rapidly and steadily, keeping almost parallel with the slope. Then, gaining an altitude of nearly five hundred feet, she circled slowly and disappeared beyond the limits of the vision of the two spectators in the pit.

Within a quarter of an hour of its leaving the cave the Zeppelin returned to earth. Anchored fore and aft it strained and staggered in the still strong wind. The officers and crew descended by means of a rope ladder, then the holding ropes were cast off and the aircraft bounded upwards. Hamerton could see that it was still connected with the ground by a flexible steel rope. The propellers were revolving and the rudders set hard over, consequently the Zeppelin was describing circles in the air at a height of a little over five hundred feet.

The words were hardly out of his mouth when the sharp, rapid detonations of a pom-pom were heard. Almost simultaneously with the screech of the projectiles sinister dark marks appeared on the aluminium cover of the Zeppelin; yet to the Sub's surprise the one-pounder shells without exception did not burst, neither did the airship appear to lose its reserve of buoyancy.

For nearly fifteen seconds the firing continued. Nearly four times that number of projectiles had been fired, many of the shot-holes overlapping each other.

Upon the conclusion of this severe test the Zeppelin was brought down, and, controlled by about fifty men holding guide ropes, was taken down the incline.

As it neared the turntable Hamerton was able to come to some conclusion as to the nature of the self-closing material surrounding the ballonettes. In one place the havoc wrought by the concentration of several projectiles had completely torn off a strip of aluminium measuring roughly two feet six inches by two feet. Within the cavity could be seen the inner lining of aluminium, which had been badly perforated, thus releasing all the hydrogen from that particular ballonette. At the edges of the perforations a substance resembling dirty cotton waste had been forced out. Only the width of the fissure prevented the closing up of the textile fabric.

As the Zeppelin was being guided on to the turntable a fragment of the plugging material fluttered to the ground. A breeze caught it and swept it towards the edge of the turntable pit. There it stopped, provokingly out of reach even if the Sub had dared to stretch out his hand to grasp it.

Just then one of the sailors manning the trail ropes kicked the piece of packing. It fell literally into Hamerton's hands.

Hamerton and his comrade exchanged glances of satisfaction. They dared not speak. They realized that they had made a great discovery.

Directly the experimental airship was safely housed the men in attendance were marched off, presumably to breakfast, and the occupants of the machinery pit were able to discuss their find.

"And asbestos fibre," said Detroit, plucking out a piece of core. "I suppose that renders the waste non-inflammable?"

"Hardly," replied the Sub. "Besides, how do you account for the stuff being gas-proof? It's as porous as a sponge."

"Ugh!" he exclaimed. "There's alum in it, and gum arabic in a viscous state, only this piece has got slightly dry. I guess I see the trick. They pack the space between the outer and inner skins with the stuff under pressure. There is not sufficient resistance to cause the shell to explode, therefore the projectile passes completely through, making only a small aperture that instantly closes behind. They made a severe test, for the Zeppelin was practically a captive balloon. Had she been travelling at from thirty to fifty knots at an uncertain range it would have been a difficult matter to get a shot home."

"Yes, firing a one-pound shell, almost the identical weapon we mount on our seaplanes. Every blessed experiment these Germans make seems directed solely against the recognized means of offence adopted by the British Government."

"Aye, coarse-charged with irregular pieces of metal in the place of the bullets used in shells when directed against troops. These Zeppelins, with their non-explosive hydrogen and their fireproof, shot-closing envelopes will be a tough nut to crack in the next war, I fancy. Look here, Detroit, old man, this stuff's worth keeping. We'll divide it into four parts, and wear it in our shoes like cork socks; then, if we are collared, we may stand a chance of keeping it in our possession."

While the two friends were thus engaged the dull boom of a gun fired thrice in quick succession struck their ears. This was followed by a bugle-call that Hamerton recognized as the "Assembly" of the German Army. This was taken up in other parts of the island till the whole garrison was aroused.

Hamerton glanced at his watch. It was just after seven o'clock, at which hour their jailers were wont to bring in the prisoners' breakfasts.

"They've discovered we've broken ship," he said. "Hans and company have found that our cells are empty. Now comes the fun."

It seemed as if the caves in the sandstone cliffs surrounding the Zeppelin station disgorged human beings, for within a few seconds of the alarm being given two hundred men were drawn up in divisions, while their officers were discussing amongst themselves the probable reason for the unexpected summons.

Up ran a portly sergeant-major. He was almost out of breath, yet he spoke in such a loud voice that the Sub was able to interpret every word.

"A message has just come through on the telephone, Herr Major," he announced; "those rascally English spies have escaped. The general orders are that all commanding officers shall post double sentries over all confidential posts; the rest of the men are to be employed in the search. No leave is to be granted until the spies are recaptured."

The major shrugged his shoulders. He was not at all pleased with the telephone message, since he had arranged to spend the following Sunday at Flensburg.

"Why have we not turned out the bloodhounds, sir?" asked a captain. "The scent must be hot."

"All the dogs were taken across to Sandinsel yesterday, Herr Major," announced another officer, a tall, fair-haired subaltern. "Colonel Dietrich wished to try the hounds on a trail laid on the sand."

"And, as a result, we have two English spies roaming over the island," added the major. Then, giving the order to march, he led the four companies under his command up the steep incline. "Now the fun commences," observed Detroit, when all seemed quiet once more. "Thank goodness they have no suspicions that we made our way here!"

"And it's lucky for us that the bloodhounds are away," rejoined Hamerton. "One never knows; they might be able to follow a trail in spite of a couple of ounces of pepper."

Before Detroit could express his opinion a deep baying sound came from the heights above.

Both men looked at each other as if to say: "We counted our chickens before they were hatched;" then, without a word, they made their way to a different part of their place of concealment whence they could command a view of the summit of the artificial cliffs.

Standing out clearly against the white drifting clouds were four large hounds. With their noses almost touching the ground they moved deliberately and unhesitatingly, while behind them walked a number of officers and men, the latter armed with rifles and bayonets.

The bloodhounds, keeping close to the brink of the abyss, gradually approached the spot where the inclined plane met the level ground of the tableland. Here they paused but for a brief instant; then they began to trot straight towards the fugitives' hiding place.

CHAPTER XIV

The Second Night of Liberty

"Hardly," he replied. "I don't believe in kicking up a fuss when we're cornered with no chance of escape. Mind you, if there were any possibility I'd fight tooth and nail. But there is not. We've had our fling, and I suppose we must pay the piper. Luckily those brutes can't get to us."

"I cotton to it," agreed the American. "I look upon it as a sort of Thanksgiving Day—a few hours of real enjoyment and then days of hard graft to follow."

On came the hounds, the mob of excited Germans at their heels. Then the animals lost the scent—that is, if they ever picked it up—for turning abruptly they made their way across to the other side of the incline. Hamerton and his companion had never been near that part of the ground.

Round and round went the bloodhounds, sniffing and baying. Shouts of encouragement from their masters failed to meet with the response that they desired. Presently one of the large beasts raised its head and opened wide its mouth. The fugitives could see the sharp white teeth and the red, frothing tongue of the brute as it gave vent to a prodigious howl.

Then, followed by the rest of the hounds, the animal retraced its steps until it gained the summit of the slope. Here the baffled trackers stood still for a brief interval. All inducements to get the dogs to take up the scent failed, and dejectedly their masters led them back to the kennels.

"Excellent, by Jove!" exclaimed Hamerton in high spirits. "The pepper did the trick, after all. Obliging Hans! He deserves a special vote of thanks."

"Guess we aren't out of the wood yet," Detroit reminded him. "What's the programme now?"

"Stay here till night," replied the Sub. "Then more investigations and grub. Man, I feel as if I could eat a joint of beef straight away. Look here, we'll strip off these wet clothes and hang them up to dry in this draught. To continue wearing them in this state is to court disaster. There's a bin of cotton waste; we'll burrow in it and snatch a few hours' sleep. It's very necessary, I think."

These suggestions were acted upon. A few days previously the two men would have regarded their proposed bed with the utmost repugnance, but, as Detroit observed, circumstances alter cases.

In less than two minutes the fugitives were sound asleep, utterly indifferent as to what befell them. Rest and slumber were the only antidotes to hunger and bodily and mental fatigue.

"Time to be up," whispered Detroit, shaking his companion by the shoulder. Hamerton roused himself. It was still daylight without, although the sun had set. Ten hours had passed like as many minutes.

Quickly they donned their clothes, which still felt clammy to the touch. Another sparse and hasty meal was partaken of, during which Hamerton took stock of the surroundings.

Work for the day had apparently ceased. Each of the airship sheds had been closed by means of the sliding steel doors, and the vast artificial basin was deserted. With the setting of the sun the wind had risen, though the velocity was not so great as on the preceding night. The sky, too, was obscured with heavy clouds. Everything seemed in favour of the fugitives.

"Wait till it's dark, then make our way up the incline, double back along the top of the cliff, and head towards the north-western part of the island. I shouldn't be surprised if we stumble across some more wonderful creations of our dearly beloved German cousins."

"But suppose there are sentries posted up there?" asked the American, pointing to the farthermost part of the slope.

"Not much! This place is all enclosed with that barbed-wire fence. That's where the sentries are to be found, and that is what is going to give us a lot of trouble."

"Not while this wind is blowing, thank you. Better to prowl about half-starved in a German fortress than to be lying on the bottom of the North Sea."

"Exactly, my dear fellow. Caution is the modern naval officer's sheet anchor. Caution is instilled into him from the moment he's placed in charge of a ship's boat under sail. No doubt it's the means of often neglecting to make full use of an opportunity; but there you are. Modern warfare has no use for fire-eating daredevils; it's the level-headed admiral who will win the next great naval war. It's prosaic, but it's hard facts. Now, easy ahead; it's time to get under way."

Making his way up the vertical iron ladder, Hamerton raised the trapdoor a few inches and listened intently. All was quiet. He emerged from his hiding place, waited until Detroit rejoined him, then carefully replaced the cover on the aperture.

Bearing in mind the experience of the previous night, how without warning the place was flooded with light, the Sub and his companion made their way as stealthily and rapidly as possible to the base of the artificial cliff where the incline merged into the circular basin. Then, keeping close to the wall, they headed towards the upper level.

Suddenly Hamerton came to an abrupt halt and stood with his back hard up against the cliff. Detroit did likewise.

Faintly discernible against the loom of the skyline was a great-coated sentry pacing up and down across the brink of the inclined plane. Barely had he turned to commence another round when a second sentry appeared on the opposite side. Both met approximately in mid-distance, faced about, and retraced their steps.

It was evident that escape in that direction was almost beyond the bounds of possibility.

Awaiting a favourable moment when the nearmost sentry's back was turned, the fugitives crept cautiously down the slope, never halting till they came to the piles of empty casks that had served them so well less than twenty hours previously.

Without mishap the two comrades gained the base of one of the ladders that reared itself vertically to a height of nearly two hundred feet. It was to be a climb that would tax their powers of endurance to the uttermost.

"Gently does it," cautioned Hamerton. "One limb at a time, mind, and don't look down. Up you go."

With this parting injunction in his mind Detroit commenced to mount, making sure of each rung before he moved a step higher. He realized that a slip might result in the loss of his comrade's life as well as of his own.

The American was in excellent training, although somewhat handicapped for want of proper food. His muscles were flexible, his grip as firm as iron; nevertheless, by the time he gained the cross-platform connecting the ladders at a level slightly above the arch of the airship shed he was glad to sit down and rest.

Detroit spoke cheerfully, but the "last lap" was roughly three times the height of the portion already climbed.

Doggedly the two men stuck to their task. Once Detroit whispered that one of the rungs felt insecure. Beyond that not a word was spoken.

Hamerton could hear the American's laboured breaths. His own heart was throbbing violently against his ribs, his arms felt as heavy as lead, while the muscles of his calves had a decided tendency to "bunch"—the forerunner of the dreaded cramp.

Many a time during his terms at Dartmouth he had climbed over the fore-topmast crosstrees of the old hulk Britannia. In those days he had thought nothing of it, but now, unaccustomed to strenuous exercises of that sort, he felt the severity of the task.

Detroit was slackening his pace now. A few inches above his head Hamerton could see the American's heels mount step by step on a seemingly endless task. It reminded him of a pet mouse in a wheel.

Up, up, up! It was by this time little better than a tedious crawl. Once or twice the American stopped to regain his breath, and then plodded resolutely on his upward way. Then, to the Sub's delight, he saw Detroit lurch forward and throw up his heels. His comrade had reached the summit, and was sprawling, wellnigh exhausted, upon the turf.

Summoning up his remaining energies Hamerton also gained the much-desired resting place. Side by side they lay drinking in the cool breeze that came straight from the foam-flecked sea, on which innumerable lights, like stars on a dark night, twinkled incessantly.

"Time!" ejaculated Hamerton, rolling over and kneeling up. "Now, easy ahead; we'll come across another wire entanglement unless I'm very much mistaken."

They were now going with the wind—the worst possible direction, since the sound of any danger in front of them was carried away, while their own approach could be heard by any sentry who happened to be to leeward.

Thirty yards from the edge they threw themselves upon the grass. Within a stone's throw was a great-coated figure standing stockstill. It was one of the chain of sentries guarding the barbed-wire fence that completely encircled the secret Zeppelin station.

Motioning with his hand, Detroit indicated that they should make a detour. Hamerton shook his head. He could just distinguish the outlines of another sentry a hundred yards to the right. "Wait!" whispered the Sub.

Presently the nearest sentry sloped his rifle and began to pace in the direction of the one Hamerton had discerned to his right. When the two met they evidently indulged in a breach of discipline, for although the fugitives heard not a word the sentries were apparently talking.

"I want to make sure of the length of his beat," whispered Hamerton. "Then the next time he clears out we'll make a dash for the fence."

Back walked the sentry. Stopping for a moment to draw up the collar of his greatcoat, for it was just beginning to rain, he made his way past the two lurking men and disappeared in the murky darkness.

Presumably the soldier was not on speaking terms with the sentry at the other end of his beat, for in a very short space of time he returned. Almost abreast of the fugitives he stopped short, faced outwards, and levelled his rifle and bayonet, as if something suspicious had attracted his attention. Then, having satisfied himself that there was no cause for alarm, he made off towards the post on his left.

"It's the rounds, by Jove!" muttered the Sub. "That's right; we'll hide in this hollow and trust to luck."

An officer and a file of men, one of whom held a lantern, came tramping through the long, damp grass. The Sub seemed to feel the glare of the light. Instinctively he buried his face in his arms and hid his bare hands under his coat. For the gleam to fall upon any light-coloured object was to arouse suspicion.

"Then don't fancy. I may as well tell you that the dogs are safely chained up. It would go ill with some of you men if they were at large on a night like this. Besides, the hounds are too valuable to risk being shot by an imaginative sentry. Now, remember, challenge once only and then fire, should any suspicious person approach your post. It means promotion to the man who succeeds in shooting or capturing those troublesome spies."

The rounds passed on. The sentry resumed his walk without attempting to give the salute. This Hamerton noticed particularly. As in the British Army, it was forbidden to give or acknowledge compliments after sunset. This knowledge he hoped to profit by, since it was within the bounds of possibility to impersonate a German officer and thus get safely away in one of the boats at the beach of the Unterland.

Silently the two comrades made their way to the fence. This time the lowermost wire was set up taut, and Hamerton had the greatest difficulty in holding it up sufficiently for Detroit to crawl clear of the sharp barbs. Before the sentry had set out on his return beat the fugitives had put a safe distance between them and that particular danger.

They were now within a hundred yards or so of Sathurn, the northernmost part of Heligoland, that terminates in a sheer cliff one hundred and sixty-six feet in height. Close to the point rises a detached pinnacle of rock, known as Hengst, its summit being only three feet lower than that of Sathurn.

"You stop here," whispered Hamerton. "The sentries seem as thick as flies. I'm going to crawl a few yards. One may escape detection where two will not."

With this injunction the Sub left his companion, and on all-fours made his way towards the extremity of the cliff. On his left was a building that a few years previously had been used as a fog-signal house. A light was burning within, and the sharp click of a shutter told the Sub that someone was using a Morse signalling apparatus.

Profiting by the glare, Hamerton crawled closer. The door of the hut was ajar. Within were several engineers standing by in readiness to work a powerful searchlight. To the left of the hut, and protected from leeward by a mound of earth, was a long metal cylinder about eighteen inches in diameter. A stray beam of light showed Hamerton that one end of this object was carefully covered by a tarpaulin.

"What's this arrangement, I wonder?" he thought. "Looks like a sort of torpedo tube. I'll——"

His hands clutched at empty air, he lurched forward, up went his heels, and the next instant he felt himself falling.

Like a flash the thought went through his brain: "I'm done for this time—I've toppled over the cliff." Yet not a sound escaped his lips, even when completely taken aback by the sudden plunge.

With a dull thud Hamerton alighted on his hunched shoulders. Instinctively he kept his head well under, and this saved him a broken neck. Inertly he rolled over on his side, wondering where he was and how far he had fallen. Nor could he help expecting to see the soldiers from the hut, who must have heard the noise of his fall.

A minute or so went by. No curious soldier appeared on the edge of the pit or whatever it was. He began to consider how he could escape.

"Solid steel, by Jove!" he exclaimed softly, tapping the substance on which he had fallen. He stood up. He found himself in a circular hollow surrounded by a wall less than six feet in height. The metal floor was perhaps thirty feet in diameter and slightly domed.

"Looks like the top of a gasometer or an oil-fuel tank," mused Hamerton. "I may as well have a short investigation. Can't stop long, or Detroit will be blundering in on top of me. Ah! What's this?"

His foot encountered a raised object. It was an armoured slide of some sort. He tried to raise it, but in vain. Then he applied pressure in a horizontal direction. This resulted in the metal slab sliding and disclosing a pitch-dark cavity.

"Wish I had a match," he muttered. "Well, here goes! I've been in worse holes than this."

His feet encountered the rungs of a ladder. Three downward steps did he take, then there was a sharp metallic click, followed by a sudden blaze of light.

CHAPTER XV

Recaptured

Fully expecting to be challenged and seized by an unseen foe, Hamerton grasped the metal slide with the intention of making a dash for liberty. As he did so the cover slipped on its groove and closed the aperture, jamming the Sub's fingers as it did so.

The pain was acute, but for the time being Hamerton paid slight heed to it. His fingers, numbed by the shock, were powerless to reopen the heavy metal cover.

Yet no hands grasped his, no hoarse voice demanded his surrender. He looked down over his shoulder, and the cause of the sudden light became apparent. In his descent he had touched a switch that was conveniently fixed to a steel upright supporting the dome. Perfect silence reigned in the place, whatever it might be.

Disengaging his fingers, Hamerton descended the remaining rungs of the ladder. He realized that the accident was a blessing in disguise, for the slamming-to of the cover plate had effectually screened all light from within. Previous to this some light might have escaped, unless intercepted by his body as he crawled through the manhole.

The chamber was almost entirely occupied by the mountings of an enormous gun. The muzzle of the weapon disappeared behind a close-fitting steel shield that effectually prevented any light from being seen from seaward. It also prevented the Sub from approximately measuring the length of the gun, but upon opening the breech block he was able to conclude that the bore was not less than fifteen or sixteen inches. The gun and its enclosed shield were of a disappearing nature, while the loading tray was so constructed that the huge weapon could be served in any position.

At the rear of the loading tray was another opening that upon investigation Hamerton found to lead to the mechanism room for elevating the gun and its mounting. Here, too, was the opening to a subterranean passage, but the door was locked. Judging by the tram rails, the Sub concluded that it communicated with the principal magazine, that must be situated, deep under the ground, somewhere in the centre of the island.

"The whole blessed island is honeycombed," he exclaimed. "It's a second Gibraltar, only much more heavily armed. What a nut for us to crack when the time comes!"

Realizing that it was about time to rejoin his companion, the Sub ascended the ladder, switched off the light, and cautiously removed the slide. The exertion told him how painful his fingers had become, while he was forcibly reminded of his fall by a peculiar numbing sensation in the nape of his neck.

Without, the monotonous click of the signal lamp in the hut still continued. The searchlight was now switched on, but the operators had made a bad contact of the carbons, for the latter were hissing and spluttering abominably. This was in the Sub's favour, for the attention of the engineers was directed upon their work, and the noise of the searchlights effectually drowned the slight scraping sound that Hamerton made as he attempted to scale the walls of the gun pit.

Thrice he essayed the task. Under ordinary conditions a six-foot wall would have presented no great obstacle, but his strength had been sapped by his two accidents.

Round the edge of the dome he crept, till at the part facing the sea he discovered an iron ladder sunk in a recess in the wall, so as not to impede the raising of the armoured gun shield and its contents.

Gaining the top of the wall Hamerton began to crawl back towards the place where he had left Detroit. He had little fear of detection from the searchlight men: his danger lay in the fact that upon crossing the beam of light from the open door his silhouetted figure might be seen by a vigilant sentry.

Fortunately his misgivings were not materialized, and without incident he crawled to the place where his anxious comrade was impatiently waiting.

"A sixteen-inch gun over there," whispered the Sub excitedly. "A regular brute. Tumbled right on top of the anti-aircraft shield."

"Only shaken a bit. Come on, it's about time we thought of something to eat. It was a quarter past one when I was in the gunpit."

"Make for the nearest house. We'll try our hands at amateur burglaring. If we keep midway between the fence and the edge of the cliff we ought to pass halfway between the double row of sentries."

It took the daring fugitives the best part of an hour to arrive at the lighthouse, a circular white tower—showing two powerful electric lights every five seconds—rising to a height of two hundred and seventy feet above the sea level. In a recent notice to mariners issued by the German Government it was stated that the lights were liable not to be shown during the manoeuvres, and plainly hinted that all merchant vessels should keep as far away as possible.

A few feet from the base of the tower stood the lighthouse-keepers' houses. The light was attended by German marines, since the fiat had gone forth that civilians were not to hold any Government post in the island of Heligoland. The keepers, with their wives and families, still occupied the same quarters as their predecessors, instead of living in barracks.

The problem now before Hamerton and his companion was which of the six houses was to be honoured by their attentions. It would be rather awkward to fix upon one where the keeper was spending his off-duty hours; in fact, an alarm raised in any one of them would inevitably bring speedy aid. But the reason why Hamerton decided upon the lighthouse quarters at all was that their comparative isolation made it easier to escape.

All the houses were in darkness. Crouching close to the ground, lest their dark figures should show up against the whitewashed walls, the two men crept from window to window, cautiously trying the fastenings.

It was now raining heavily, while around that exposed position the wind howled dismally. Hardly a night for a dog to be out, yet here were two men of good social position groping in the rainswept mire in their quest for food and liberty.

Hamerton raised himself and peered through one of the windows. A fire burned in the open grate, a dull-red pile of coals. The Sub rightly concluded that it had not been touched for several hours. By its glare he could see rows of well-scoured highly-polished metal pots and pans, doubtless the pride of a thrifty German housewife; and, what was more pleasing, a couple of shelves on which stood bread, cold meat, cheese, and a glass jug half filled with an amber-coloured liquid.

On either side of the fireplace two high-backed chairs were drawn up. Both were in shadow, being shielded from the glow of the embers by an outstanding oak mantelpiece. In front of the grate stood a large iron pot, its contents still simmering gently. The Sub could almost imagine that he smelt the savoury odours.

He tried the window. It was secured by a heavy metal catch. Nothing short of breaking a pane of glass would enable him to force an entrance. The sight of the eatables was wellnigh irresistible.

Here, sheltered from the wind and rain, the two chums discovered that a small window had been left unsecured. In a trice Detroit was up on the Sub's back and was through the narrow opening. Hamerton could not have done it to save his life, for his whole body was aching painfully. He had perforce to wait until the American stealthily unlocked the door.

Hamerton's first act was to draw a curtain over the window, then the two famished men began to wolf the eatables, standing close to the fire to enjoy the comforting glow, the while reckless of the consequences, for their clothes were steaming like a hard-pressed horse on a frosty day.

Suddenly Hamerton touched the American on the shoulder and held up a warning finger. Overhead was a scuffling sound; then thud, thud, the noise of a heavy person descending the stairs.

Their retreat was cut off. Hamerton crouched behind one of the armchairs, Detroit took refuge under the table, and there they waited, hoping that the newcomer would not notice the depletion of the larder.

The click of the key in the lock and the rasping of the bolts told them that either the occupier of the house had imagined that the door had been accidentally left unsecured, or else that there were nocturnal intruders—and "the cat was out of the bag".

Alas for the first theory! The electric light was switched on, and from his place of concealment Hamerton could see the skirts and big carpet slippers of a portly female.

One glance was sufficient to show the woman that thieves had been at work. Stooping, she peered under the table, and Detroit's eyes met those of one of the fattest women he had ever seen.

Without raising a shout the woman made a dart for a rifle that stood in the corner. This she accomplished with considerable agility considering her bulk.

In one corner of the dresser were several loose cartridges. It was towards these the woman waddled.

"Stop her," hissed Hamerton, springing from his place of concealment. He was in time to grab the keeper's wife and prevent her from obtaining the ammunition, while Detroit grasped the rifle.

Then ensued a long struggle. The woman was powerful and determined, the intruders, loath to harm a female, did their best to wrench the rifle from her without exercising brute force. And the curious part about it was that the woman from first to last never called for help.

Finding he could not gain possession of the weapon, the Sub deftly extracted the bolt and thrust it into his pocket.

"Be sharp, Detroit," he exclaimed. "Unlock that door. That's right. Now help me to secure this lady. She's deaf and dumb, poor creature. Hand up that curtain cord. You tie her ankles while I keep her from hitting you over the head with this rifle."

It was easier said than done. The woman resisted bravely, but at length the American succeeded in passing the cord round her ankles and drawing it tight. Then by their united efforts the two men lowered her gently on to the stone floor.

"Now let's cut," said Hamerton. "If anyone in the next house but one heard the scuffle—— Put the top of that loaf in your pocket before you go."

Into the blinding rain the fugitives made their way, pausing under the lee of a low stone wall in order to get accustomed to the darkness.

"Now there'll be a rumpus," whispered Detroit. "The best thing we can do is to get back to our quarters under the turntable. Since the place is well guarded they won't expect to find us there, especially as they're bound to know that we've been pillaging one of the keepers' cottages."

"That's so," assented Hamerton. "Plucky old woman, that. She would have used that rifle if she had managed to get hold of those cartridges."

"She has, I guess!" exclaimed the American, starting to his feet as a loud report came from the house they had just left. The housewife, unable to make herself heard, had contrived to raise herself by means of the table, seize a cartridge, and throw it on the fire.

Keeping the lighthouse on their right the fugitives bolted, their one idea being to put a respectable distance between them and the keepers. Already lights were appearing in the cottages and a babel of shouts arose, men enquiring what was amiss, and offering various suggestions as to the cause of the alarm.

Soon the deaf-and-dumb woman was released, and by means of signs told how she had been molested by the two English spies.

With that there was a general exodus. The keepers, intent upon winning the reward issued for the escaped prisoners' arrest, seized their rifles and started in pursuit. Not having the faintest notion of the direction the fugitives had taken, they naturally concluded that they had made for the Unterland in the hope of being able to seize a boat. All this while Hamerton and Detroit were making towards the circular fence surrounding the Zeppelin station.

"Easy!" whispered the Sub, when they were nearly abreast of Spitz Horn. "We'll be tumbling upon the sentries if we are not careful. They have been warned for a dead cert."

Before Detroit could reply a tall, dark figure loomed up directly in front of them. A levelled bayonet glinted dully in the dim light and a guttural voice bade them stand on the pain of being instantly shot down if they resisted.

Oswald Detroit had not been a full back of his college team to no purpose. With a sudden panther-like spring he threw himself upon the ground right under the levelled bayonet.

The sentry made a bold attempt to shorten his weapon and lunge at his antagonist. He was the fraction of a second too late. The American's steel-like fingers gripped him round the ankles. His bunched head and shoulders caught the German a tremendous battering-ram-like blow just above the knees.

Swept off his feet by the impetus, the sentry fell heavily on the ground. As he fell his finger involuntarily pressed the trigger of his rifle. There was a deafening report. The bullet whizzed close to Hamerton's ear, while he clearly felt the blast of the detonation.

There was not a moment to be lost. The man's comrades, already on the qui vive, saw the flash and heard the report. The nearmost of the cordon ran to support the fellow who had raised the alarm.

Throwing themselves on the ground the Sub and his companion crawled in a direction that was practically at right angles to the imaginary line between the two nearest sentries. As they did so they heard the swish of a man's boots shearing through the long, damp grass.

Once more luck was in their favour, for the oncoming sentry passed them within a distance of ten yards. So intent was he upon finding his comrade that the two men lying prone upon the ground were unobserved.

With an exclamation of dismay and astonishment the German stooped over the body of the insensible soldier. Others came running up, and in the darkness one called attention to a dark object fifty yards or so from him, moving cautiously in the direction of the lighthouse.

Half a dozen shots rang out. The object, whatever it was, gave a convulsive spring and collapsed, kicking in its death agonies.

Off ran the sentries to investigate. They had shot a goat that had strayed from one of the adjacent gardens!

This diversion enabled the fugitives to gain the fence without detection, wriggle under the lowermost barbed wire, and find a temporary respite on the unpatrolled area between the entanglement and the brink of the Zeppelin pit.

With considerable difficulty the American located the topmost rungs of one of the vertical ladders.

"Yes," replied the Sub grimly, yet he knew that he had hardly an ounce of strength left.

"Follow on," continued Detroit. "If you feel fagged, give me the word and I'll hang on to you while you rest."

Although the descent entailed considerable less exertion than the ascent a few hours before, Hamerton could hardly retain his grasp upon the slippery steel rungs. His downward motion was purely mechanical. His joints seemed so stiff that a sharp racking pain shot through his shoulders every time he lowered an arm to find the next rung.

"No, carry on," begged the Sub, "if I stop I'm afraid I won't be able to continue. It's only another fifty feet or so."

"All right!" replied his comrade dubiously. "But, say, shall I carry you down? hang on my back."

Suddenly Detroit came to a halt, groping aimlessly with his foot for the next rung.

Gripping one side of the ladder as far down as he could he felt with his free hand. The disconcerting discovery that the lowermost section of the ladder had been removed came as a sudden and nerve-racking shock.

"Up we go," he exclaimed, with false cheerfulness. "We've struck the wrong ladder. It ends here. We've only to get back to the horizontal platform."

Retracing that twenty feet was almost beyond Hamerton's strength. Had it not been for his companion's aid the Sub would certainly have relaxed his hold. Utterly exhausted, he threw himself upon the light, steel bridge connecting the vertical ladders, and shivered through sheer weakness and bodily anguish.

"Stay here," continued Detroit. "I'll go on a little tour of investigation. When I come back I'll rub your wrists and ankles, and then we'll make short work of getting to the ground."

Stepping over Hamerton's body the American made his way along the face of the cliff. He was filled with vague fears. Something seemed to tell him that all three ladders had been tampered with.

Just as he gained the part of the bridge immediately above the opening of one of the Zeppelin sheds, every arc lamp in the pit was instantaneously lighted.

Blinded by the sudden and powerful glare the American stopped stockstill, grasping the light handrail, and vainly attempting to shield his eyes from the intense brilliance of a lamp just beneath the place where he stood.

Voices hailed him in an unknown tongue. Their import was plain enough: it was a peremptory summons to surrender.

He removed his hand from his eyes. He could now see, though indistinctly. Fifty feet beneath him and as many yards from the base of the cliff stood a squad of marines with levelled rifles. Behind them were three or four officers who had demanded his instant submission.

Detroit had sense enough to realize that the game was up. He raised his hands in token of surrender, then deliberately made his way back to where Hamerton stood.

Luckily for him the officers saw his object, and forbore to order their men to fire. Several sailors came running up, bearing the displaced section of the ladder. This they placed in position, and half a dozen of them swarmed up to seize their prisoners.

"It's the fortune of war, old man," exclaimed Hamerton feebly, "but we've had a very good innings."

CHAPTER XVI

The News Leaks Out

"Here's a letter from Kiel for you," announced Octavius Smith as he entered the cabin of the Diomeda. "You're a rum card, Stirling; you generally manage to get hold of everything you want. Bless me if I ever thought you'd get a reply from Pfeil."

"It's quite about time," replied Gordon Stirling unconcernedly as he caught the envelope his companion tossed towards him.

Ten days had elapsed since Stirling had set out to carry off a journalistic scoop. Allowing for two Sundays, that were not counted in ordinary leave, only six more days remained. In less than a week he would have to be slogging away in the Inland Revenue Office at Lowestoft, making up arrears of work that his confrères were bound to keep open for him. That is one of the ethics of a Government Department. A fellow returning from leave is supposed to be like a young giant refreshed with wine—ready and willing to tackle any accumulative work. The result is that almost all the benefits from a holiday are thrown away upon a desperate attempt to reduce the pile of bookwork to reasonable dimensions.

For days past the westerly breeze had held. Smith was beginning to fret at the enforced detention, especially as he learnt from meteorological reports that only a few miles to the north the wind was almost exactly in the opposite direction.

"I'll read you Pfeil's letter. There are one or two words I can't make out without a dictionary, but I can make a very good guess at them:

"DEAR SIR,—

"In answer to your letter, I hasten to send this by the next dispatch. I know your friends, Herr Hamerton and Herr Detroit, are in Heligoland, so there must be a mistake in the story that they met with a disaster. How I know is this: my brother Sigismund is in S174, one of the boats operating with us when I fell overboard and was rescued by your friends. Directly I was landed I wrote to him assuring him of my safety, and describing the yacht and her crew who treated me so kindly. In his reply he told me the English yacht was lying off Heligoland, and that Herr Hamerton and his friend had landed to be the guests of one of our German officers. The next day the yacht was towed away—I think it was to Bremen—to undergo some repairs. The Englishmen remained. Five days ago my brother's torpedo-boat destroyer S174 left for the purpose of towing her back to Heligoland. She has apparently been delayed by bad weather, for she has not yet returned. This ought to dispel any doubts in your mind concerning an accident to your friends. We leave for Stettin to-morrow on a three-weeks' cruise.

"With respects,
"Yours,
"HANS PFEIL."

Smith puffed vigorously at his pipe for a minute or so. His knitted eyebrows showed that he was deep in thought.

"Fishy; decidedly fishy," he remarked. "Stirling, you stand a chance of pulling off your scoop after all. It is fishy—very. The Diomeda, lying here in Delfzyl, is supposed to be at Bremen for repairs. The German destroyer S174 is supposed to be sent to tow her back. I wonder whether that vessel that is persistently hanging about off the entrance to the Dollart is S174?"

"We'll find out," said Stirling decisively. "Come along. Van Wyk will be able to tell us."

"The number of that German destroyer?" he repeated. "I know not; but since you are curious I can find out. Come with me to the quay; the Maas has just returned. It is possible that Captain Jan will be able to tell us."

Captain Jan van Hoes, the skipper of the botter Maas, was sitting on the brightly painted skylight of his craft. A long pipe was in his mouth; his hands were deep in his voluminous pockets; his legs, encased in stiff baggy, trousers, were thrust out straight in front of him.

"Passed that German craft, aye, that I did," said the old skipper, without removing either his pipe or his hands. "Steaming south-south-west about four miles outside Rottumeroog. S174 was her number. Saw it through my glass as plainly as I can see the town-hall clock."

"Thank you for your information," said Stirling, offering the old fellow a gulden. Captain Jan looked at the coin, began to draw one hand from his pocket, and then slowly thrust it back again.

"I want no money for doing nothing, Mynheer," he said. "You are welcome to what I have told you."

"Look here," began Smith, when the two Englishmen regained the deck of the Diomeda, "this job wants any amount of tact. I don't think I'd telegraph the information. It will keep a few hours longer."

"Get back to London as fast as you can. Don't mind me; I can hang on here very comfortably. See your editor and explain matters to him. He'll be able to deal with the business far more diplomatically than either you or I can. If he thinks fit to publish the news, well and good; but my private opinion is that he will communicate with the Foreign Office. The British and United States ambassadors in Berlin will be instructed to ask a few questions, and in less than a week Hamerton and Detroit will be set at liberty."

"Then there'll be war between Great Britain and the United States on the one hand and Germany on the other, unless Germany climbs down. Popular sentiment will be raised to such a pitch that war will be inevitable. But Thompson won't, except as a last resource. Now pack up and clear out. You'll just manage to catch the Harwich boat."

Sixteen hours later Stirling entered the private office of Harold Bennett, the editor of The Yachtsman's Journal. Bennett eyed him sadly, for Stirling's "special" looked as if it meant a financial loss to the already slender resources of the paper.

"I've found out something," exclaimed Stirling excitedly. "Hamerton and Detroit are alive. They are in Heligoland. There is every reason to believe that they are imprisoned as spies under the names of John and William Smith."

"Then why in the name of thunder didn't you wire? We've just gone to press, and there'll be nearly a week's delay. I'm bound to inform Thompson, and by next Friday the news will be as stale as anything. Anyhow, let's have the story."

Not a word did Bennett speak while Stirling was relating the incidents of his stay at Delfzyl and expounding his theories. Occasionally he would make a pencil note on his blotting pad.

"I quite agree with you, Stirling," he said at length. "A precipitate disclosure would be most injudicious. I'll ring up Thompson.

"You must. Stirling, my special, has just returned from Holland. Very important news."

"Very well then." Thompson glanced irritably at the half-completed "leader" on his desk. "Half an hour. Ring off."

It was more than two hours before The Yachtsman's Journal editor and Stirling left the offices of The Westminster Daily Record. They did not leave alone. Thompson accompanied them, having delegated the completion of his leader to the sub-editor.

Outside the offices the three men entered a taxi and were driven to the Foreign Office. The presentation of Thompson's card was a sure passport to the sanctum of Sir Theophilus Brazenose, the Secretary of State for Foreign Affairs.

Sir Theophilus was essentially a strong man. He was active in mind and body, prompt to act, yet displaying a natural caution that on many occasions had stood him in good stead, and had piloted the nation through many an international crisis.

"You are quite right, Thompson," he remarked, after carefully listening to the editor's narrative, and perusing the letter which Stirling had received from Hans Pfeil. "This is a delicate situation. Extreme reticence and secrecy are essential. Of course I quite agree with you that this German seaman's name should not appear in any dispatches forwarded to our ambassador in Berlin. It would result in the severest punishment being inflicted upon him by the German Admiralty for his unquestionable indiscretion, however serviceable it may be to us. By all means refrain from making the news public. I will decide what is to be done as soon as possible. Meanwhile, Mr. Stirling, let me offer you my congratulations on your zeal, tact, and astuteness."

Stirling bowed. In his mind he was wondering whether Sir Theophilus would be so lavish with his praises if he knew that he (Stirling) was a civil servant drawing a paltry salary of a hundred a year.

"You'll be in town for a few days, I hope?" asked Thompson, when the three journalists returned to the offices of The Westminster Daily Record. "I hardly know. You see, my leave is up next Saturday."

"Yes; I'm not on the regular staff of The Yachtsman's Journal. I'm in the Inland Revenue Office at Lowestoft."

"Chuck it, my lad. Send in your resignation. You're merely wasting your time there. I'll offer you a post at two hundred and fifty pounds as special correspondent; permanency, mind you, with good prospects; send you back to the Continent till this Heligoland business is finished with."

Two more days passed. The Secretary of State for Foreign Affairs was in constant telegraphic communication with the British Ambassador in Berlin. The most elaborate cipher was used, and precautions taken to prevent leakage of unauthentic information.

The Ambassador was instructed to apply to the German Government for permission to interview John and William Smith, the condemned spies; the authorities at Berlin hedged. They took umbrage at the somewhat unusual request.

Suddenly a journalistic bombshell burst upon the British public. In The Morning Remembrancer, a "rag" with a comparatively limited circulation, appeared the following, in heavy type:—

"Advice from our own correspondent reveals the startling fact that the identity of the two persons sentenced, under the names of John and William Smith, to five years' detention for espionage has been made known. The victims of an international outrage are Sub-Lieutenant John Hamerton, R.N., and Mr. Oswald Detroit, son of Senator Jonathan Detroit, of Norfolk, Virginia, U.S.A. The story of their supposed tragic fate in the North Sea, being reported to have been lost overboard from the yacht Diomeda, is still fresh in the public memory. Further startling disclosures are imminent. We understand that representations have been made to Germany by the Governments of Great Britain and the United States for the immediate release of the alleged spies."

Stirling happened to be at the office of The Westminster Daily Record when Thompson's attention was called to the dramatic announcement in the rival publication.

Thompson was not usually a man to give way to outbursts of temper. He was generally brusque, deliberate, and level-headed, but on this occasion his fury for a few moments was uncontrollable.

"Someone has sold us!" he shouted. "That wretched rag has got the laugh at us. If I could only get hold of the fellow that supplied the information—it wasn't you, Stirling?"

"I believe you. Sorry I asked the question." Thompson was growing calmer by this time. "It's bad enough for our reputation to let a rival collar what is by right our scoop. Makes my blood boil. And, not only that, there's a fresh danger of an international rupture. A little diplomacy would perhaps have settled this spy business. Sir Theophilus Brazenose has the matter in hand, and now the fat is in the fire. Just you 'phone to Bennett and ask him if he knows anything about the matter."

But before Stirling could get connected the editor of The Yachtsman's Journal hurriedly entered.

"Seen this, Thompson?" he asked, holding up a folded copy of The Morning Remembrancer.

"Of course," replied Thompson dryly. "It does not do to go about with one's eyes shut. All the same, it's a bad business; another case of journalistic integrity letting one down pretty badly."

"Calling at the Foreign Office. It's close on ten, and Sir Theophilus will be there at that hour. Come along, and you too, Stirling."

"One moment," said Bennett. "You will be losing precious time. Get a special out. Explain matters, and ask the public to reserve judgment until the Foreign Office has had its say."

Without a word Thompson sat down, took up a pencil, and began to scribble. There was no hesitation; the point of his pencil glided over the paper at a rapid pace, yet each letter was formed as clearly as if it were copperplate.

"With reference to the report appearing in the columns of a contemporary, it will doubtless be interesting to know that the material facts brought to public notice have been known to this journal for some time. Since it is our principle to take our readers into our confidence, we now have no hesitation in stating the actual facts of the case. Our special commissioner returned from the Continent on Monday last, bringing with him the startling news that the spies condemned under the names of John and William Smith were supposed to be Sub-Lieutenant Hamerton, R.N., and Mr. Oswald Detroit, an American citizen. We venture to suggest that our contemporary has no actual proof that such is the case, and we throw out a challenge to that effect.

"Immediately upon receiving our commissioner's report, we, together with the editor of an influential yachting journal, waited upon Sir Theophilus Brazenose, Secretary of State for Foreign Affairs, and laid the matter before him. Sir Theophilus acted immediately, issuing instructions to the British Ambassador in Berlin. At the same time he urged upon us the necessity of withholding the news from the public until our commissioner's report was either confirmed or contradicted.

"This we cordially agreed to do, in the belief that it was in the interests of the nation. Unfortunately the news has leaked out through some obscure channel. We therefore ask the public to refrain for the moment from making any demonstrations of antagonism towards a friendly Power, and to leave the issue confidently in the hands of His Majesty's most able Minister for Foreign Affairs."

"That ought to act as a cold douche to our hot-headed friends on the staff of The Morning Remembrancer," observed Bennett. "Now, we'll be off to the Foreign Office."

They found Sir Theophilus considerably perturbed at the ill-judged announcement in The Morning Remembrancer. He realized the danger of a popular outburst.

"The nation ought to be roused to a pitch of indignation should Mr. Stirling's report prove correct," he observed; "only, there is this radical point: we have no proof. It is evident that some subordinate has been induced to impart confidential information, and this catchpenny journal has jumped to the conclusion that Mr. Stirling's suppositions are absolutely correct. They may be, of course, but on the face of it the action of the German authorities seems preposterous."

"Yet Stirling is emphatic upon the point that Hamerton and his American friend are in Heligoland. There is also definite proof that a German destroyer is dodging about off the Dollart. There was also a report spread about to the effect that the yacht was towed to Bremen for repairs, while all the time she was lying at Delfzyl," observed Thompson.

"There is certainly ground for strong suspicions," admitted Sir Theophilus. "I frankly admit that we have often to act on rumours far less trustworthy than these. However, we can only await a reply from the British Embassy at Berlin. Meanwhile there is popular opinion to be taken into account. I think that——"

A tap on the door, followed by the entry of one of the under-secretaries, caused Sir Theophilus to break off abruptly. The subordinate, observing that his chief was engaged, was about to back out of the door, when Sir Theophilus asked him what he wanted.

"Here is a copy of the special edition of The Westminster Daily Record, sir," he announced. "There is a leader on the Heligoland affair. I thought perhaps you would care to see it."

"So you could not refrain, Mr. Thompson?" asked Sir Theophilus, with a suspicion of reproachfulness in his voice.

The Secretary of State began to read. As he did so his visitors narrowly watched his features. Gradually the frown on his brows relaxed.

"Excellent, Thompson, excellent!" he exclaimed. "You've tackled the business with most praiseworthy skill. We can now only await developments. Rest assured that as soon as I have a communiqué from the Embassy I will send for you again."

But in spite of the efforts of the editor of The Westminster Daily Record, the storm raised by the rival journal attained huge dimensions. There were indignation meetings in almost every town and village of the United Kingdom. Letters abusing the Government and accusing the Foreign Office of being weak-kneed and incapable poured in by every post. Shouts of "Down with Germany" were raised in Parliament Street and in Trafalgar Square while intolerant demands were made that the Fleet should proceed to German waters and smash the Teutonic Navy to smithereens.

Nor was the anti-German outburst confined to this side of the "Herring Pond". From New York to San Francisco, and from the Canadian frontier to the shores of the Gulf of Mexico, the usually level-headed citizens of the greatest republic on earth shouted for revenge for the insult offered to one of their sons. It required the greatest diplomacy on the part of those in authority tactfully to curb the impatience of millions until the fateful report from Berlin should arrive.

The British and United States Ambassadors at the German capital lost no time in presenting a polite yet firm demand that they should be permitted to have access to the two condemned spies. To this the Kaiser's ministers promised their consideration.

Meanwhile General Heinrich von Wittelsbach had been hurriedly summoned to Berlin. He fully realized that there was danger ahead. There were two courses open to him: either to confess his error, explain his motives, and throw himself upon the clemency of his Imperial master; or else to take a high hand, stanchly declare that no mistake had been made, and appeal to the Kaiser not to lower the dignity of the Hohenzollerns by submitting to the arrogant demands of the ambassadors of Great Britain and the United States.

He chose the latter course. It would mean either victory or dishonour, whereas by the former course nothing but disgrace would be his portion.

It was at a levee in the imperial palace of Potsdam that the Emperor questioned the governor of his fortress of Heligoland.

"Sire, I give you my solemn word—the word of a soldier—that neither the English officer, Hamerton, nor the American, Detroit, is in the Island of Heligoland."

Therein he spoke truthfully, for before leaving for Berlin the commandant had ordered the removal of the prisoners to the adjacent island of Sandinsel.

CHAPTER XVII

The Sandinsel Tunnel

After their recapture Hamerton and Detroit were shut up in separate cells, the former in the same place as before, while the American was lodged in a disused casemate of the Bucket Horn Battery.

Their captors left nothing undone to guarantee the safety of the prisoners. Hamerton's cell had been recemented over the original floor to a depth of four inches of solid concrete. The bars of his window had been removed and others of considerably greater thickness securely let into the stonework. An observation hole had been cut in the doorway, and the jailers were given instructions to visit the prisoners' cells every two hours, day and night.

Every few hours wireless messages came from Torpedo-boat-destroyer S174. They brought slight consolation to Von Wittelsbach's peace of mind. The long-sought-for yacht still remained alongside the quay at Delfzyl.

Then came the news that an English newspaper had published the information that the spies were Sub-Lieutenant John Hamerton and Oswald Detroit, an American subject.

Von Wittelsbach was for the time being speechless with rage and mortification. He anticipated the order to proceed to Berlin to give an explanation, and ere he set out he gave instructions that the prisoners should be removed to Sandinsel.

It was late at night when a file of marines entered Hamerton's cell. The sergeant in charge roughly ordered him to get up and dress. Although still weak with the effects of his brief spell of liberty, the Sub was rapidly recovering. Two days' rest was sufficient to banish the pain in his neck caused by his involuntary dive into the secret gunpit of the Breit Horn battery. His bruised fingers gave him considerable inconvenience, so that he took a long time over his dressing operations.

"Hasten," ordered the sergeant more than once, but Hamerton paid scant heed. He was resolved not to retard the healing of his hand by unnecessary haste, since he might even yet have an opportunity of eluding his captors.

The fragments of the prepared cotton from the fireproof Zeppelin he still retained in his shoes, but the steel spike which had served him so well had been discovered and taken away by his jailers soon after his recapture.

"Roll your blankets," ordered the non-commissioned officer gruffly. You are to take them with you."

"Evidently I am off on a long journey," thought the Sub at this stage of the proceedings. "What's up now, I wonder? Judging by the elaborate alterations they have made to my quarters I thought they meant to keep me here for a very long time."

"March!" ordered the sergeant, pointing to the door. "No tricks, mind. Our rifles are loaded."

Along the corridor, down the steps, and out into the open the file of marines conducted their prisoner. Then the gates in the outer wall were thrown open, and the Sub found himself in the street.

Turning sharp to the left the party marched along the broad, even road leading towards the Zeppelin station. It did not take them long to arrive at the barbed-wire fence. Hamerton could not help contrasting the time it took with the tedious, cautious crawl over that very ground only a few nights before.

Here the marines were challenged by a sentry. The sergeant advanced, whispered the password, and received permission to proceed.

A large extent of the fence had been levelled, and over the barbed wire were placed the metal coverings Hamerton had noticed during his tour of investigation.

Down the familiar incline the Sub was hurried, till the marines halted within twenty yards of the circular expanse out of which opened the caves for the giant aircraft.

Everything was now in darkness, but by the presence of numbers of soldiers and seamen Hamerton concluded that one of the Zeppelins was about to be hauled out for a nocturnal flight. He wondered vaguely if he were to be an involuntary passenger.

A sliding door opened in the cliff, revealing a long passage lit at regular intervals with electric incandescent lights. A waft of hot, moist air greeted the Sub as he entered.

The tunnel was only wide enough to admit of two men walking abreast. Along the ground ran a narrow-gauge tram line. At every twenty-five yards or thereabouts was a niche, intended as a refuge for foot passengers upon the approach of any rolling stock. For the first hundred yards the tunnel was on the downgrade, then it was horizontal in direction. Overhead, and above the hollow tramp of his escort, the Sub could hear a dull, muffled roar: it was the sea. The tunnel, then, was passing under a portion of North Haven.

Hamerton calculated that he had gone quite a mile through the tunnel ere the upward gradient commenced. One hundred and twenty paces more and the prisoner and his escort were confronted by a steel door. On either side was a deep recess. In one of them stood a portly soldier in the uniform of the fortress artillery. Apparently he had already received his instructions, for, with a familiar nod to the non-commissioned officer in charge of the party, he unlocked and rolled back the sliding door.

For half a minute or so Hamerton could see nothing. The sudden transition from the well-lighted submarine tunnel to the blackness of the night temporarily deprived him of his sense of sight.

He gradually became aware that he was in a stone gallery open to the heavens, but additionally protected by mounds of earth and sand piled well above the level of the enclosing walls. To bind the soil, thorn bushes had been planted. These also served to screen the gallery from observation, while as a protection from shell-fire traverses had been provided.

Just above the summit of one part of the mound Hamerton could see a quaintly-shaped iron tower, the light from which was occulted every three seconds.

Now he knew exactly where he was. The opening of the tunnel was about a hundred yards north-west of the North Beacon of Sandinsel. Where the latest British Admiralty chart showed an expanse of sand covered at high water, his sense of vision told him that a vast extent of artificial ground had risen from the sea.

Another thing struck him in a very forcible manner: on either side of the gallery were hung rectangular steel plates, measuring roughly ten feet by six, and painted in a medley of colours. It was like the so-called "invisible" colouring on the guns and gun-shields of British fortifications, the idea being that at a distance the various hues would blend and form a neutral tint. But in this instance the metal plates were hinged at the top edge. They could be raised by means of levers, and thus form a V-shaped covering to the gallery, presumably as a protection from high-angle fire or from explosives dropped from a hostile airship.

But Hamerton had little leisure to observe these things. The sergeant waited until he had received the password for the Sandinsel portion of the fortress, and then gave the order to march.

The enclosed way seemed interminable. For one thing, it never ran in a straight line for more than twenty yards at one time. Here and there other galleries branched both to left and right—the majority to the right. In places huge armoured bridges crossed the concealed way. On one a travelling crane, electrically propelled, was in the act of crossing.

The whole place seemed alive, judging by the sounds. The Sub could hear the sharp rattle of pneumatic riveters, the peculiar scroop of electric drills, and the thud of ponderous hammers, punctuated by the deafening hiss of compressed air. From a greater distance came the monotonous grinding sounds of a fleet of dredgers at work. There was no mistaking that: Hamerton had seen and heard dredgers at work in the principal naval ports at home. The groaning, rasping noise as the heavily-laden buckets come jerkily up the "ladder", the succession of dull thuds as bucket after bucket throws its contents of mud, sand, and larger stones down the shoot into the hopper, could not be mistaken for anything else.

Hamerton was puzzled. A fleet of dredgers—or even a solitary one—could be heard miles off. Yet during his enforced detention at Heligoland he had never heard the faintest sound that suggested operations of that nature.

"Well, it's either one of two things," he thought. "Either the cliffs of Heligoland possess strange acoustic properties, and deflect the sound entirely, or else these vessels have started work to-night for the first time—at least, since I set foot upon the island."

His musings were cut short by his escort coming to an abrupt halt outside a postern. Here, in front of the neutral-grey-coloured sentry-box—which had recently superseded the parti-coloured diagonal lines for which the German military authorities had a predilection—stood a sentinel with his bayonet at the "ready".

Even when the sergeant of the escort gave the password he was not permitted to pass the gateway until the rest of the corporal's guard had been turned out. Those responsible for the safety of the West Kalbertan Battery had evidently made up their minds to take no chances.

Hamerton saw very little of the interior of the fort that had only recently been constructed on foundations formed of ferro-concrete piles sunk twenty feet through the sand and another thirty feet in the stiff clay that composed the subsoil.

The West Kalbertan Battery had been well placed. Its armament, consisting of six fifteen-inch guns and a number of light quick-firers, commanded the only approach to North Haven from the north. It was one of a chain of six batteries—the others being the East Kalbertan, the Krid Brunnen, the Düne, the Aar de Brunnen, and the Sud Sandinsel—that were supposed to render Sandinsel impregnable. It was this heavy fortifying of the former sandbank that caused the German engineers to mount nearly all their heavy guns on Heligoland on the south-west side.

Then, although the guns of Heligoland commanded the approaches to the Elbe and the Weser, the batteries of Sandinsel were actually the key of the position. Whoever was master of Sandinsel was master of Heligoland.

Hamerton was lodged in the upper story of a building within the fort which was mainly devoted to non-combustible stores. The walls were not so thick as those of his former prison, the floors were planked, while the ceiling was of ordinary plaster. The solitary window was fairly large, glazed, and protected by iron bars that had apparently only been placed in position a few hours before, for the cement was barely dry.

Almost immediately on the departure of the escort a lieutenant, accompanied by two non-commissioned officers, entered the room. The officer was a fair-haired youth of about twenty. His rounded features and blue eyes gave him almost a girlish appearance, which his incipient moustache failed to destroy.

"Ach! Herr Smidt," he began in tolerable English, "I hope you give no trouble. You cannot escape you out of here—you take my word. If no trouble, then perhaps we allow you insignificant privileges. So."

The Sub looked at the speaker. The German officer seemed a decent little chap, he decided.

"I had a rough time of it when I broke out of prison before," he replied. "Perhaps I may not have the opportunity or the inclination to do so, especially as I am promised certain privileges if I behave. But, Herr Lieutenant, let me inform you that I do not answer to the name of Smith."

The lieutenant smiled and tapped his forehead in a significant manner. The act irritated Hamerton almost beyond endurance, but the thought suddenly struck him that perhaps after all the German really thought he had to deal with a prisoner whose brain had become affected.

"No; my name is not Smith," continued the Sub earnestly. "I'm Hamerton, an officer of the British Navy. Don't you believe me?"

"I tell you this," he said. "Herr Hamerton sailed from here in his yacht. He was lost at sea; his comrade also. You will do yourself no good if you acclaim yourself as Herr Hamerton. Smidt you are, and I believe you know it. Now be good, and no trouble give."

With that the lieutenant took his departure, and Hamerton was left in the dark and to his own resources. There was nothing further for him to do at present, he reflected; so, unstrapping his blankets, he turned in and was soon fast asleep.

When he awoke the sun was shining brightly, and by its position he knew that his window faced north-east. He had barely completed his toilet when his breakfast was brought in.

"Evidently they mean to treat me better than they did at Heligoland," he reflected, as he looked at the larger cup of coffee, the long roll, a pat of butter, and a couple of fried mackerel. "This seems too good to last."

He set to with a will, for he had a healthy appetite. As he ate he could not help thinking of his conversation with the German lieutenant. The man seemed perfectly open about the matter, as if he really believed the prisoner was under a hallucination.

Then his thoughts turned to Detroit. What had they done with him? Had he been brought to Sandinsel, or was he still in solitary confinement in Heligoland?

His meal ended, Hamerton crossed over to the window. The outlook was not particularly extensive. Immediately below was a kind of courtyard, with triple lines crossing it in several directions. This system enabled heavy wagons to be run over the broad gauge, and lighter trucks to use one of the outer rails and the intermediate one.

The outer space was bounded by the inner part of the fortifications—an almost blank wall pierced by a few doorways and apertures for ventilation.

Hamerton could not see over the wall, but he knew by the presence of a screen of furze and gorse that the face of the fortifications was composed of earth and sand, the best material for minimizing the effects of heavy projectiles.

There his range of vision ended, save for the expanse of blue sky overhead. He might sit at the window for days at a stretch and still see nothing of a confidential nature. Save for an occasional fatigue-party and the passing of a carefully-covered-in train of trucks drawn by electric tractors, the courtyard was deserted. Everything in connection with the actual working of the guns was concealed under the wide mound of earth and sand on the other side of that stone wall.

"A truly cheerful prospect," thought the Sub. "To gaze upon this outlook is a rare intellectual treat. I must make the best of it, I suppose. It is only in old romances that the governor's daughter, or at least the jailer's daughter, takes compassion upon the hapless captive, provides him with a safe disguise, collars the keys from her parent, and releases the object of her affections. This fortress is controlled by men of blood and iron. Sentiment and romance find no place in this modern German Gibraltar. Well, it's no use moping I'll have a look round the room."

It did not take Hamerton long to make a careful examination of the interior of his prison. With a steel tool in his possession he would be able to cut his way out with far less exertion than he had to spend on his previous attempt. The window was but fifteen feet from the ground; with his strength he felt confident that he could bend the long iron bars sufficiently to allow him to squeeze through. Failing that, five minutes of uninterrupted work would be enough for him to knock a hole in the plastered ceiling and make his escape on to the roof. But to what purpose?

He was surrounded by the formidable walls of the West Kalbertan Battery, and, even should he be able to scale the ramparts and evade the sentries, there was not a place of shelter in the whole of Sandinsel where he could hope to remain hidden for even an hour.

"The Monte Cristo wheeze is played out," he mused. "It might be possible to knock down the jailer and put on his clothes, if it were not for the fact that there are always two men waiting outside. Besides, there is the password, which I haven't got. That suggestion is no good. I remember reading of an authentic case of a man in a debtor's jail getting hold of a strip of raw liver and laying it across his throat. The jailer, thinking his prisoner had put an end to himself, ran out of the cell, and in his fright forgot to close and lock the door. The prisoner made good his escape. That was a neat trick; but then that was not within the walls of a modern fortress. It's a case of wait and see, only with more of the waiting and considerably less of the seeing, I fancy."

Yet he did not fall a victim to black despair. He was eminently of a very sanguine disposition, and, recognizing the truth of the saying that "while there's life there's hope", he made up his mind to keep bodily fit, so as to be able to take full advantage of any chance that fortune might throw in his way.

The Sub looked about him for some object to practise with. The chair caught his attention. It was a solid oak one with a rush bottom, just the thing to use as a bar bell and keep his muscles pliant.

His still tender fingers caused him some misgiving, but with very little effort he raised the chair above his head. To his great delight he found that the stiffness of his neck and shoulders was hardly noticeable.

Up and down he swung the chair. For one thing, it killed time; it also kept him in training. He revelled in the exertion.

Suddenly the door opened, and the soldier detailed to act as his jailer entered. Hamerton faced round, his improvised gymnastic apparatus still poised above his head.

With a yell the fellow dropped the earthenware basin on the floor and backed hurriedly out of the door, shouting at the top of his voice that the Englishman had gone mad.

A picket was hastily told off, and, accompanied by the fair-haired lieutenant and a surgeon, the soldiers entered the Sub's room, to find Hamerton calmly sitting on the chair.

"Is this the way you promise to behave?" questioned the lieutenant. "What have you done?"

"Exercise? Mein Gott, your form of exercise very remarkable is, Herr Smidt. Now you be sensible. I give you one more chance. If you behave not, then I report to Herr Major Kohn, and you will be put in far worse place."

The lieutenant and the surgeon walked out of the room, followed by the men; but half an hour later another jailer appeared with a pile of books, "for the use of Herr Smidt, with the compliments of Lieutenant Schaffer."

CHAPTER XVIII

The Errant Airship

The next day was warm and sunny, with hardly any wind. It would have been an ideal day for cricket, thought Hamerton, as he gazed through the window upon the deserted courtyard. It made confinement doubly hard and irksome.

Continuously the noise of machinery and the busy hum of workmen rose in the sultry air. The smell of petrol and occasionally wafts of hot mineral oil seemed to pervade the atmosphere.

Yet above the din could be heard the dull roar of the sea: the sullen breakers lashing themselves into masses of white foam upon the inner edges of the Hohe Brunnen shoal. It was a sure sign of a storm far out to sea.

The Sub was listless. In vain he tried to fix his mind upon the books the fair-haired lieutenant had lent him. It was all to no purpose. Again and again he threw down the volume and returned to the window to look upon a vista of paving stones and an almost blank wall.

At about three in the afternoon a shadow, travelling at a great pace, fell athwart the courtyard. It could not be a cloud, for the sky was of a deep-blue colour and destitute of any form of condensed vapour.

Presently he saw the reason for the shadow. It was a huge military Zeppelin, larger than any he had yet seen. Owing to the altitude of the airship it was difficult to judge her dimensions, but by a rough-and-ready comparison with the height of the men who formed her crew, Hamerton came to the conclusion that she was at least eight hundred feet in length, forty-five feet in height and about seventy feet in beam. Not only did she have three cars slung underneath, but on the upper surface of the outer aluminium envelope was a broad gangway, terminating at each end in a wedge-shaped deck-house.

At first Hamerton could see only the rails of the gangway, but as the airship stood farther away to the eastward he discovered four guns so mounted as to be able to fire in a vertical direction, besides being able to be trained abeam.

With the naked eye the Sub counted thirty-two men on board. Others were doubtless in the nacelles, so that he estimated that the crew numbered not far short of fifty.

Unlike the British dirigible, the craft was painted a dull grey on her under body and an olive green above the line of her greatest perimeter. The only splash of bright colour about her was the black cross ensign of Germany that flew from a short staff at the after end of the upper platform.

As the Zeppelin passed over the West Kalbertan Battery her speed was at least thirty miles an hour; but even as the Sub watched she lurched forward and settled down to a pace of nearly thrice her former rate.

In a very few moments she was lost to sight, although flying at an altitude of nearly a thousand feet, travelling in the direction of the North Sea entrance to the Kiel Canal.

"Unwieldy brute!" ejaculated the Sub. "I wonder what headway she would make in a gale of wind? It's a fine day, so I suppose they are taking their pet gasbag for an airing. It strikes me pretty forcibly that they'll have to be pretty sharp about it, for that ground swell is a certain sign of a gale."

Twenty minutes later an air squadron consisting of seven seaplanes flew overhead. The Sub regarded them with curiosity. He had heard that the German authorities, after repeated experiments, had decided to build a number of improved seaplanes to be stationed on the Frisian coast, and now for the first time he saw them in actual flight.

They were flying low—at less than a hundred and fifty feet above the ground; but they flew none the less steadily. The floats were really three boats, the centre one big, about twenty feet in length, and decked in with the exception of two small wells. Immediately in front of the foremost one was a one-pounder automatic gun protected by a V-shaped shield. Abaft the after cockpit was a machine gun of the Maxim type.

On either side of the main float was a subsidiary one, serving simply as outriggers to give lateral stability to the seaplane when resting on the surface of the sea.

Between the floats, and suspended from rods running in a fore-and-aft direction, were a dozen cylindro-conical objects that the Sub recognized as bombs for dropping upon hostile ships and fortifications.

It was clearly evident that all the power of offence was distributed on or between the floats, leaving the rest of the seaplane for elevating, steering, and propulsion purposes. The main planes were comparatively short in distance from tip to tip, but broad in proportion. The fabric was apparently of light, non-flexible metal, curved with the convex side uppermost, while both planes were set at an angle of about sixty degrees to the centre line. There were two propellers, one set slightly below the planes, the shaft being driven by means of a chain connected with the engine. The second propeller, worked on a shaft within and projecting beyond the main shaft, was so arranged that its rotation was in an opposite direction to that of the after one. By this means the after propeller "gripped" the air thrown back by the foremost one, and a considerable increase in speed was claimed to have been obtained.

Extending right aft for a distance of ten feet beyond the vertical rudder was a long hollow pole made of aluminium. Surrounding it was a canvas covering, secured at the end nearest the main planes by a metal band. This device was supposed to be for the purpose of saving life should the seaplane become disabled in mid-air and be unable to volplane down to the surface of the sea. By drawing the metal band forward the canvas would be distended by the wind and thus form a huge parachute. Provided the crew were not thrown clear of the falling craft they would be able to descend with it at very little risk.

An experiment had been tried in Kuriche Haff only a few days previously. A seaplane was hoisted to a height of two thousand feet by a dirigible. The parachute safety band was released, and the craft dropped. It fell erratically for nearly a hundred yards before the parachute became fully distended; then, tilting nose downwards, it continued descending in a series of spirals, its rate being greatly retarded. Striking the surface of the water the seaplane dived till half the length of her floats and a part of her main planes were submerged. Then, like a cork, she leapt clear of the surface and settled naturally on her floats.

Hamerton, of course, was ignorant of this highly-confidential test, but the unusual sight of a pole projecting far in the wake of the seaplanes attracted his attention. At first he came to the conclusion that it was a form of aerial torpedo tube, till it suddenly occurred to him that it might be a form of arresting the attraction of gravity in the event of an accidental downward plunge.

Almost as soon as the seaplanes passed out of sight Lieutenant Schaffer entered the room, accompanied by the two men who acted as jailers.

"Yes," replied Hamerton; then, on the spur of the moment, he added: "I see you have adopted the parachute principle in the event of an accident?"

"Saw it with my own eyes," replied the Sub, delighted at the successful guess he had made. "I thought your people would collar the idea from us sooner or later."

"Collar? What do you mean?" asked Schaffer, completely mystified. "Collar? That something is around the neck—dog collar, horse collar, stylish collar, hein?"

"Crib? Ach, I haf it! Crib something is to do with children. You say our Zherman air fleet it is in infancy, eh? You are all wrong, as you will see."

"I said nothing of the sort," said Hamerton, smiling. "I said you collared, cribbed our ideas—sneaked them."

"I understand not still," expostulated the German lieutenant. "I haf not learned the word 'sneak' in my vocabulary."

"You then have a like device in England? Then it is by spies such as you, Herr Smidt, that it was made known."

Whatever had been his object in entering Hamerton's cell the Sub never found out, for the lieutenant lost no time in informing his superior officer that these English had already got to learn how to prevent disasters to aircraft heavier than air.

As Hamerton had foreseen, the gale began to make itself felt. Just before sunset a strong breeze from the east sprang up, and in less than twenty minutes the Sub could see columns of spray dashing high above the seawall between the East Kalbertan Battery and the Düne Fort.

As darkness set in the wind increased in violence. Clouds of sand and salt spray were flung against the window of the Sub's room, the furious blasts howled over the chimney pots and through the overhead telegraph wires.

Then the searchlights were switched on. The giant beams swung slowly to and fro, till at one moment the upper part of the wall opposite Hamerton's window was as brilliant as polished silver, at another as black as Erebus.

Still no rain fell. Up to the present it was a gale of wind, one that would blow itself out in a comparatively short space of time.

Hamerton had no thought of going to bed. He stuck to his post at the window, fully expecting to see the giant airship come battling with the gale in an endeavour to find shelter in the cavernous sheds on the island of Heligoland.

Suddenly, above the howling of the elements, a bugle rang out. From the barrack quarters within the battery issued scores of men dressed in brown-canvas working suits. Without waiting to form up they ran in the direction of the main gateway. Clearly something of the nature of an accident had occurred to warrant this hasty nocturnal parade.

Then Hamerton saw the reason. Picked out by several searchlights the giant Zeppelin appeared. She was battling bravely against the wind, but slowly and surely was being driven astern. She was flying low. Her commander evidently decided that it was too hazardous to attempt to return to her proper berth, and was endeavouring to descend under the lee of the East Kalbertan Battery, where a shallow depression in the wake of the low walls offered the only possible though doubtful shelter. With the thought of previous disasters fresh in their minds the Germans dreaded the possibility of being blown far out to sea. They would not even take the risk of sheltering to leeward of the lofty Heligoland; they preferred to attempt to secure the unwieldy airship on Sandinsel.

Lower and lower sank the Zeppelin, till her nacelles were hidden from Hamerton's eyes by the intervening wall. Her way seemed momentarily checked as ropes were thrown to the hundreds of waiting soldiers. As fast as they could move, two-thirds of her crew slid down to earth, only the officers and twelve men remaining until the Zeppelin should be properly secured.

"I wish the blessed thing would smash up," thought the Sub. "Not that I want any lives to be lost, but because the Germans crow over their wonderful airships and construct elaborate castles in the air for the humiliation of England."

Even as these thoughts flashed through his mind the airship swung round broadside to the wind. In an instant swarms of men were being lifted off the ground or being dragged over it like dead flies on a resinous string. Gamely they struggled to keep the errant aircraft under control, but in vain.

Rapidly the Zeppelin drifted towards the West Kalbertan Battery, till her huge envelope loomed high above the fortifications. With a dull thud the nacelles struck the earthworks. The frail aluminium gave before the shock, and the remainder of her crew, with one exception, were precipitated upon the sand.

Relieved of their weight, the Zeppelin bounded upwards for a distance of about ten feet, just clearing the formidable wire entanglements. Then a downward eddy seemed to strike her, and she dropped till the fragments of her cars touched the pavement of the courtyard. The nearmost portion of her aluminium envelope was now within thirty yards of Hamerton's window. He realized that nothing short of a miracle could prevent the unmanageable craft from buckling itself against the angle of the storehouse in which his cell was situated.

With praiseworthy devotion the soldiers still hung on to the guide ropes till the foremost of them were hauled to within a few feet of the barbed-wire fence. Thrown into a blaze of silvery light by the searchlights, the entanglements became strikingly apparent to the luckless soldiers. It was more than flesh and blood could stand—being slowly dragged over an expanse of sharp iron barbs. In a moment the guide ropes from the after-end of the Zeppelin were abandoned.

The next thing Hamerton saw was a shower of tiles, bricks, laths, and plaster falling about him, to the accompaniment of a succession of most appalling crashes.

Instinctively he leapt backwards as a twisted and distorted mass of metal was forced through the aperture. Between the rents in the masonry the slanting beams of half a dozen searchlights played upon the dust-laden atmosphere. The grinding of the enormous body of the Zeppelin, added to the roar of the wind and the shouts of dismay of the baffled soldiers, formed a fitting accompaniment to the scene of desolation.

A train of thoughts flashed across the Sub's mind. He realized that he was in imminent peril of being crushed like a rat in a trap beneath the falling brickwork, for one side of the room was already showing signs of sharing the fate of the part facing the original direction of the impact. A sudden resolution seized him. Better by far to make a rush for the tangle of aluminium rods and sheeting and trust to be lifted clear of the debris than to remain in danger of the collapsing walls.

With a quick, lever-like wrench the remains of the nacelles described a complete semicircle. The Zeppelin, free for'ard, was swinging round on her heel, like a ship that has struck stern foremost upon a submerged rock. Then, with a comparatively slow yet determined movement, the wreckage began to assume an upward motion.

Hardly realizing what he was doing, Hamerton sprang over a heap of bricks and dried mortar, and grasped one of the vertical rods that still connected the damaged car with the outer envelope of the gas bag. Half-blinded with dust, his grotesque clothing rent almost from his back, he found himself being raised from the ruin of his cell. He felt the cold breeze of the open air upon his heated forehead.

Then, hardly knowing whether he was on or above the ground, he flung his legs round the twisted rod to which he had clung so desperately with his hands. Even as he did so the side wall of his cell collapsed. Another few seconds and he would have been crushed to death beneath the debris.

Released from the restraining wall, and no longer held in semi-captivity by the swarm of men, who had been compelled to relinquish their hold upon the guide ropes, the damaged Zeppelin bounded to a height of nearly a hundred feet, the while being urged onward at a tremendous pace towards the rocky cliffs of Heligoland.

The Sub was not one to lose his nerve even in a tight corner. His first step was to gain a place of greater security than that afforded by a trailing rod that ended in space less than three feet beneath him. Hand over hand he climbed, till he reached a metallic beam that at a very recent period formed one of the fore-and-aft girders of the lower gangway.

Here he sat in comparative safety. He could rest until he regained his breath ere he made another bid for greater safety.

The wind no longer howled through the chaos of broken and twisted rods. Borne along at almost the same velocity as that of the gale, the Zeppelin was apparently floating in the still air, although in reality her speed over the ground was now not much less than sixty miles an hour. Assailed on all sides by the brilliant searchlights, the derelict aircraft was heading straight for the cliffs at Bucket Horn. Unless she lifted herself sufficiently to clear the one hundred and twenty-eight feet of cliff she would inevitably be dashed to pieces against the sandstone bluff.

Shading his eyes from the blinding glare, Hamerton could see the precipitous wall of rock momentarily growing larger and larger. Thirty feet were wanting to clear the edge of the cliff. It seemed as if nothing could save the uncontrollable Zeppelin.

Hamerton set his jaw tightly. He fully realized the danger. He was mentally picturing the impending disaster, the bulging sides of the envelope charging the cliff and being crushed like an empty eggshell against the inflexible wall of sandstone. The remains of the nacelles would be swung violently inwards, the concussion would result in his being dislodged from his position and being flung heavily upon the rocky, breaker-swept ledges at the base of the island.

Yet the expected did not happen. An upward eddy, caused by the wind being deflected by the perpendicular cliff, tossed the Zeppelin in its boisterous grip.

Her stern portion, being lighter than the bows, since most of her weight had already been torn away from that end, swung clear of the cliff. Hamerton could see the roof of a searchlight shed slip past barely twenty feet beneath him. Then came a sudden jerk that wellnigh dislodged the Sub from his precarious position. Only his tenacious grip saved him.

The whole of the enormous bulk of the Zeppelin seemed to pause momentarily, then with a sickening, heaving motion the aircraft shot upwards to an additional height of five hundred feet. In swinging past the brink of the chasm the destruction of the machinery compartment of the midship nacelle was completed, and her motors, weighing little short of a ton and a half, were precipitated to the ground, rolling into a concealed gunpit and greatly damaging the breech mechanism of the weapon.

Just then a loud roar came from one of the forts, the powerful Spitz Horn Battery. The Germans, despairing at the loss of the pride of their aerial fleet, and fearful lest she should be borne by the gale to the shores of the hated England, had decided upon the expedient of riddling her with heavy shells. In the hope that their vaunted hole-closing fabric would in this instance prove unequal to the conditions laid upon it, the gunners used the secondary armament of twenty-six-centimetres weapons.

With an unearthly shriek the first projectile, weighing nearly three hundred pounds, passed harmlessly above the envelope of the errant Zeppelin, bursting with a lurid red flash at a distance of five hundred yards behind her. Two more shells followed, almost simultaneously. These fell far beneath the rapidly-moving target. Although the aim in a vertical plane was good, the artillery-men were hopelessly at a loss as regards elevation. The Zeppelin, now only faintly visible in the rays of the distant searchlights, was out of range and well on her way across the stormy North Sea.

CHAPTER XIX

At the Mercy of the Winds

It would ill describe the state of mind of the deputy commandant of the fortress of Heligoland to say that he was thunderstruck at the latest disaster that had overtaken one of the German air fleet. It was he who had given the order for the gunners to bring down the derelict. Their failure to do so only increased his consternation. He was almost in a state of stupefaction. At one moment he raved at the indiscretion of the commander of the Zeppelin in attempting to come to earth in a gale of wind; at another he sat with his hands clasped tightly across his eyes, as if trying to shut out the inglorious sight of the hitherto peerless airship drifting helplessly at the mercy of the elements.

Then came the disconcerting news that one of the spies had escaped. The ruins of his cell had been hastily examined without any trace being found of his body, and it was owing solely to the statement of one of the men, who said he believed he saw the Englishman clinging to the wreckage, that the authorities came to the hasty, but none the less accurate, decision that such indeed was the case. This stirred the second commandant to action. He ordered the whole of the second flotilla of torpedo-boat destroyers to proceed at once to sea, in the hope that they might overhaul the errant Zeppelin should the gale moderate.

In less than ten minutes from the time of receiving the order the first of the destroyers left South Haven, followed with commendable celerity by her consorts. Regardless of the high-crested seas they steamed under forced draught. Dense clouds of black smoke, tinged with dull-red flame, belched from their squat funnels, which speedily became white with salt. Swept fore and aft, even at the risk of carrying away most of the deck gear the frail vessels rushed through the blackness of the night, spreading fanwise between north-west and south-west in order to cover the possible limits of the object of the search.

Meanwhile a wireless message in code was dispatched to the German Admiralty. It was useless to conceal the magnitude of the disaster, but one point was omitted. No reference was made to the supposed presence of the English spy upon the derelict. That information was sent only to General Heinrich von Wittelsbach, who was on the point of returning to resume his command.

The fates seemed to be working against Von Wittelsbach. Almost on the top of his carefully-worded denial to his emperor came the disquieting report that Hamerton was on board the fugitive Zeppelin. The commandant's sole hope lay in the destroyers which had been dispatched in search of the truant. Should they fail, it was more than likely that the airship would either be driven across to Great Britain or else fall into the sea. Her huge bulk could hardly pass unnoticed by the scores of British trawlers at work on the Dogger, since from the direction of the wind the Zeppelin would be blown directly over that great fishing ground. In either case Hamerton stood a fighting chance of being saved, and then the truth would out.

Early on the following morning Von Wittelsbach embarked on a light cruiser that had orders to await him at Cuxhaven. Twenty minutes later the vessel anchored in South Haven. The destroyers were even now returning from their fruitless search; their wireless messages told the same tale with monotonous and depressing regularity; and to add to the irony of the situation the short summer's gale had blown itself out, and the sun shone brilliantly from a cloudless sky. The sea had subsided, and only a long oily swell served to remind the fisher folk of the Frisians and the shores of Schleswig-Holstein of the storm that had wrought havoc on their coasts.

For the rest of the day General von Wittelsbach remained shut up in the Government House, waiting and waiting, hoping against hope that the threatened exposure of his duplicity might yet pass away.

Throughout the short summer's night Hamerton clung to his frail support. He gloried in his position. Nothing seemed to trouble him. Here he was floating in hundreds of feet in the air, and being rapidly borne westward by the partially crippled Zeppelin.

The aircraft, being entirely out of control, was nothing more than a non-dirigible balloon. For the most part she drifted broadside on to the wind, occasionally describing a pendulum-like motion in a horizontal plane. Otherwise she was fairly steady, with hardly any tendency to dip her bow or stern. The air was warm, the threatened rain had not fallen, the airship seemed far above the surface of the sea, and showed no inclination of descending. By occasional bearings from certain well-known stars, the Sub derived the consolation that the westward drift was still maintained.

Day began to break: a grey light in the north-east betokened the approaching dawn and the coming of fine weather. This latter circumstance was not pleasing to the self-constituted crew of the airship. He realized that with the falling of the wind the progress of the Zeppelin would naturally be retarded. His wish was to place as many miles betwixt himself and his prison isle as he could in the shortest possible time. He had counted upon that; but if hung up in the middle of the North Sea the airship stood a chance of recapture by German torpedo craft, or destruction by the guns of the Teutonic seaplanes, which he fully expected would be sent for that purpose.

The exhilaration of the pure air raised his already buoyant spirits. He felt as if he could dance a hornpipe even on the narrow girder on which he sat. Instead, he began to whistle, till the effort reminded him very forcibly of the pangs of hunger.

It was now light enough to see about him. He found himself just in front of the ruins of the after nacelle, that looked almost exactly like a railway carriage with the floor knocked out. Abaft were the remains of two of the propellers, with only one blade left intact. The alley way communicating with the midship and foremost cars was originally outside the outer aluminium envelope. This had been torn away for a length of nearly a hundred feet, only the longitudinal girders and a few vertical rods remaining.

Could the Sub successfully make his way over that intervening space he would be able to find ample floor space in and on each side of the central nacelle, that had practically escaped damage.

It would be a risky performance, but Hamerton decided to hazard it. It was like "laying along" the foreyard of a square-rigged ship, only without the footropes. Instead, there was the grip afforded by the still-holding aluminium stays, which, although more than an arm's-length apart, could be made good use of, provided the climber did not lose his balance when halfway between.

Standing upright upon the narrow metal track Hamerton mentally measured the distance to the nearmost upright rod. It was roughly about eight feet. In two rapid but deliberate strides he gained the first halting place of his short but hazardous journey. Two more stages gave him increased confidence, and the next thirty feet he negotiated with comparative ease, in spite of the gentle undulating motion of the aircraft.

Then came an absence of any support for his hands for a space of thrice the distance between those he had just passed. Beyond that the rest of the way would be easy, for several partially-rent plates, that at one time formed partitions of the envelope, still remained fixed to the girder.

Three steps did he take, when his foot slipped. Vainly he tried to regain his balance; the sag of the badly-supported girder, combined with the swaying of the airship, prevented him from so doing, and with outstretched arm he fell sideways off the slender framework.

His left hand caught in the girder, the flat edge rasping the skin almost to the bone. His fingers gripped as only those of a man used to working aloft could do: once again his training on the old Britannia stood him in good stead.

Like a flash he threw his right arm over the girder. There he hung, dangling in mid-air, with the imminent prospect of dropping eight hundred feet or so, to be smashed to a pulp as his body struck with fearful velocity the surface of the North Sea.

Not for a moment did he lose his head when once he felt his hands gripping the T-shaped girder. He knew that it would only be a waste of energy to attempt to clamber back; his one and only chance was to make his way forward to a place where the bent and jagged aluminium sheathing would afford precarious foothold to enable him to gain the still-intact platform in the wake of the midship nacelle.

With a slight effort Hamerton raised his legs sufficiently to enable his heels to rest on the upper face of the girder. His weight was thus more evenly distributed, and his arms were no longer taxed to their fullest strength. He was now clinging with hands and feet to the under side of the aluminium beam, with his nose only a couple of inches from the lowermost flange of the T-section.

Slowly he edged towards the place whence he hoped to scramble into safety. Inch by inch, foot by foot—the distance seemed interminable. Not for an instant did he look down. He knew only too well the fatal consequences that that indiscretion would entail.

At length his feet touched the metal plate. It was still riveted by the upper edge of the girder, hanging downwards at an angle of about thirty degrees and curling to almost a complete circle near its lower edge.

Cautiously he swung his feet from off the beam. All his weight now fell upon his fingers. Then his shoe came in contact with the curved part of the plate. The aluminium sheet gave slightly, but Hamerton found, to his unbounded relief, that it offered sufficient resistance to the pressure to permit him to relax his grip with his right hand.

He lost no time, however, in shifting his grasp so that both hands were on the same side of the girder. Now he was able to half-turn, so that both feet rested on the curl of the plate.

Summoning his remaining energies, Hamerton sprang. His foothold was sufficiently good for the purpose, although the twisted plate gave slightly under the pressure. The next instant he was lying on the deck with his legs dangling over the edge.

Now that the immediate danger was over, he felt dizzy and sick. For a moment or so a white mist swam before his eyes. Had the airship lurched to port he might have fled into space without being conscious of making an effort to save himself.

After a while the Sub roused himself and took stock of his surroundings. The platform was barely six feet in width and twenty in length. On the starboard side was a handrail, which had escaped the fate that had overtaken the greater part of the suspended portions of the aircraft. Aft, the platform broke away suddenly, leaving only the girder which had caused Hamerton such a hazardous journey. The other end terminated at the bulkhead of the midship nacelle, access to which was gained by a narrow sliding door.

Even as he looked a hand grasped the edge of the sliding panel, apparently with the intention of drawing it open. In a moment Hamerton was on his feet. His dizziness was past, the new phase of danger that threatened him aroused all his energies. It was quite possible that several of the crew might have remained on board; if so, there were complications ahead.

In vain Hamerton sought for a weapon with which to defend himself. There was nothing: all the twisted aluminium bars within reach were firmly secured to the platform. He must make the best use of his fists.

It required considerable effort to double his powerful hands, owing to the strain of hanging on to the girder, combined with the lacerated condition of his palms. But having arrived thus far in his bid for freedom, Hamerton was not the man to knuckle under tamely; he meant to make a hard fight for liberty.

The sliding panel was giving the unknown a lot of trouble. Owing to the violent shocks that the airship had experienced, every part of the framework had been strained, and in this instance the door was tightly jammed.

Another hand appeared in sight. It was not that of a second man, but only the left hand of the still unseen member of the crew. For fully half a minute the fellow wrenched at the non-yielding door, then, giving up his task as a bad job, he relaxed his hold.

A dull thud, followed by a deep groan, told the Sub that the danger had been exaggerated. Without hesitation he made his way to the door, and with a heave of his brawny shoulders sent the panel clattering into the recess intended for it.

Lying at full length on the floor of the car was a man dressed in the uniform of a lieutenant of the German Navy. His forehead was caked with dried blood, his clothes were rent till there was little to choose between the rags which covered Hamerton's frame and those of the injured man.

"It is quite evident that this poor fellow is the only member of the crew left on board," reasoned the Sub, "unless, of course, there are some lying stunned in the wreck of the fore nacelle. Otherwise they would have come to his assistance long before this."

He bent over the wounded officer. The lieutenant was quite unconscious. His chief injury, Hamerton found by a hasty examination, consisted of a bruise over the right temple. In the centre of the forehead was a deep, clear cut that could be treated lightly, although the appearance of the congealed blood made the wound look far more dangerous than it actually was.

The midship car was principally devoted to officers' cabins, there being two on the port side of the through gangway and one to starboard. The contents of all three had been completely wrecked by the concussion. Water bottles and jugs lay smashed to fragments upon the floor. In the midst of the debris he noticed a razor; this he carefully set aside, vowing to remove the straggling beard that was beginning to make itself particularly aggressive at the first opportunity.

For'ard of the nacelle, and adjoining the place formerly occupied by the motors, were two large tanks, one on either side of the gangway. One had been "started", a large rent showing in the sheet metal. The other was intact, and full of water.

"Salt!" ejaculated Hamerton disgustedly. "Water ballast, of course. It may come in handy though."

Continuing his forward pilgrimage the Sub reached the wreckage of the foremost car. Here the twelve-pounder gun had fallen through the floor, leaving jagged portions of the floor plates sufficiently wide to allow the Sub to gain the interior. In one corner of a subdivision of the compartment stood a metal freshwater tank, and close to it, in a rack, a number of cups. Without delay the Sub, carefully carrying a small quantity of water, made his way back to where the wounded officer lay.

The German was still insensible. Drawing a handkerchief from the unconscious man's pocket Hamerton dipped it in the water and proceeded to wash the cut in his forehead. As he did so he recognized that fate had thrown an old acquaintance across his path, for the officer was Lieutenant Schwalbe, the same who had effected Hamerton's arrest on board the Diomeda.

Having attended to the injured man as well as the limited means at his disposal would admit, the Sub decided that it was time he made an examination of the aircraft that had under remarkable circumstances come under his command.

Looking down over the rail he found that the Zeppelin was maintaining a height of about a thousand feet. Unknown to him the vessel had dropped to less than a fifth of that distance just before dawn, but with the rise of temperature following sunrise she had regained her former altitude.

The sea was still foam-flecked, and, although it was impossible to form an accurate description of the state of the waves from that height, Hamerton had reason to suppose that the gale had not yet blown itself out.

Allowing the average rate of the derelict to be forty-five miles an hour, he came to the conclusion that she was now—unless the direction had changed—within a hundred and fifty miles of the Northumberland or Berwickshire coast.

As far as the eye could see the surface of the water was unbroken by any vessel large or small. The North Sea seemed entirely deserted.

The pangs of hunger, that had been temporarily banished while the Sub was attending to the injured Schwalbe, now reasserted themselves, and after a short search Hamerton discovered the officers' pantry, practically intact. After the hard fare he had been accustomed to during his enforced detention at Heligoland the meal that followed seemed the best he had ever had in his life, his appetite whetted by the bracing air and the joyous satisfaction that he had regained his freedom.

A shave and a wash still further heightened his satisfaction, and, the deficiencies of his wardrobe demanding attention, he had no scruples in throwing overboard his ragged parti-coloured uniform of captivity and donning a greatcoat and trousers of one of the officers of the airship.

"By Jove! I wonder how the crew got to the platform on top of the envelope?" he exclaimed. "I really must see what the 'Mount Misery' of a Zeppelin is like."

His first effort in that direction was to make a thorough examination of the sub-compartments of the midship car, but no signs of a means of gaining the elevated deck were forthcoming. Nor would he again risk the hazardous way along the single girder to the remains of the after nacelle.

Again he went for'ard. Almost immediately within the bow nacelle, and to the right of the sliding door, was a vertical flight of steps formed by means of steel bars set across an angle of the compartment.

"These must lead somewhere," he argued, "although they don't appear to. So here goes!"

From the third step he was able to touch the aluminium plating that formed the ceiling of the nacelle. His hand came in contact with a metal knob that had in the gloom hitherto escaped his notice.

Backwards and forwards he strove to move this object. It seemed immovable. He tugged, pushed, twisted it all to no purpose.

"Like everything else on board this blessed packet the thing's jammed," he growled. "I'll get a cold chisel from the armourer's chest and cut a hole through the plate. Great Christopher Columbus! what's that?"

A bell was ringing violently in some part of the aircraft. Perhaps, after all, there were more of the crew still at their posts on the upper platform?

He was about to descend, when, his eyes getting more accustomed to the gloom, he caught sight of a bolt placed at less than a foot from the knob that had so completely baffled his efforts.

He drew back the bolt. The flap above his head immediately swung back on a pivot, disclosing a long tunnel-like shaft. Simultaneously the bell ceased to ring.

"What a silly ass I am!" declared Hamerton. "I see the game. By touching that knob a bell rings for the purpose of warning those on deck that someone is ascending. That is quite feasible, since two persons could not pass each other in this exaggerated tin-whistle pipe."

Without hesitation he commenced to climb. The interior of the tube was of polished aluminium and reflected shafts of light that entered from the open top. He could see the blue sky overhead.

It was a long climb, for the vertical passage was nearly fifty feet in height. It reminded the Sub of the interior of a battleship's mast. A faint scent of hydrogen assailed his nostrils. Whether it was an accidental leakage sufficiently serious to affect the buoyancy of the airship or merely the natural wastage from the ballonettes the Sub knew not.

Upon gaining the upper platform Hamerton's first act was to inspect the fore-and-aft shelters. Both were deserted. They were also practically intact. The standard compass for'ard was in working order. More by force of habit than anything else he glanced at the card. The Zeppelin's bows were pointing due east—exactly the opposite direction to the way he wanted.

This was a most disconcerting discovery. To be ignominiously borne back into German territory was humiliating. Rather than let that happen he would attack the ballonettes, liberate the hydrogen, and allow the aircraft to settle, half-water-logged, on the North Sea.

Hamerton glanced at his watch and found it was a quarter to five. That puzzled him, since by the position of the sun it must be nearer eight o'clock. A second look showed him that his watch had stopped. He remembered that, contrary to custom, he had omitted to wind it.

Presently a thought struck him. Walking to the end of a transverse bridge he looked downward. A long way below and far from the perpendicular a large shadow was cast upon the sea. It was the shadow of the airship across the sun's rays. For a full minute he watched it intently, then he gave a sigh of relief.

In his mild panic in noting the direction of the Zeppelin's bows he had forgotten that, drifting at the mercy of the winds, she was liable to swing horizontally in any direction. By observing the direction of the path of the shadow his mind was set at rest. The airship was drifting nearly sou'-sou'-west.

"That's much better, thanks be!" he ejaculated fervently. "If this continues I shall land, not in the north, but somewhere in Norfolk or Suffolk. Perhaps within sight of Lowestoft. But I'll swear the blessed ship is lower than she was. I wonder where I can find the altitude gauge? And the wind is falling too. That shadow shows we are travelling at a bare twenty knots."

Just then the Sub gave a hasty look round over the vast circle of sea. Something caught his eye. He looked steadily for a few seconds to make sure there was no mistake.

Less than five miles off was a large torpedo-boat destroyer, pelting along at top speed. Her commander had spotted the Zeppelin, of that there could be no doubt. Was the oncoming craft one of the German destroyers, dispatched to recapture or destroy the errant airship?

CHAPTER XX

Homeward Bound

"It's a pure piece of bluff—that's my opinion," declared Thompson. "The most remarkable thing about the whole business is the quiet way in which the British and United States Governments have accepted the German authorities' explanation."

Thompson, Bennett, and young Stirling were seated in the former's sanctum at The Westminster Daily Record's offices, just off Whitehall.

"Well, what else could they do under the circumstances?" asked Bennett. "They couldn't very well tell His Imperial Majesty that he was telling a deliberate untruth; now, could they?"

"Hardly. No, it's the old story—international diplomacy, which, reduced to its simplest form, means which party can tell the biggest lie without being found out."

"But we've proof," objected Bennett. "Why on earth wasn't the German Admiralty asked to produce the alleged spies in spite of their assurances?"

"What actual proof have we?" he asked. "Only a letter from a German sailor stating that a friend of his saw Hamerton and Detroit on the island of Heligoland on the same day as they were supposed to be washed overboard. The fellow might have made a mistake, all in good faith, or he might be playing the fool with Stirling."

"But there's the instance of the German destroyer persistently cruising off the Dollart. That tallies with Pfeil's statement that the Diomeda was to be taken possession of and brought back to Heligoland," persisted the editor of The Yachtsman's Journal.

"I quite agree with you. There seems something strange about the whole matter," replied Thompson. "For the moment I am a self-constituted mouthpiece for our friends the enemy. Again, the German sailor might be mistaken; while, since a part of the Dollart is German waters, one of the torpedo-boat destroyers is quite at liberty to cruise about there, I take it."

"Quite so," agreed Bennett affably. He was about to play his trump card. He paused while he lit a cigarette, and then continued: "I've had the tip, my dear Thompson, that the Admiralty have given orders for the torpedo-boat destroyer Boxer to proceed from Sheerness to Delfzyl tomorrow morning, to tow the Diomeda back to Lowestoft. What do you make of that, eh?"

"Stirling," said Thompson quietly, "there's a job for you. I believe you can be regarded as one of the yacht's crew? Good! I'll 'phone to Sir Theophilus and ask him to get you a passage on the Boxer."

Before two that afternoon the head of the Foreign Office obtained the necessary permit from the Admiralty, and at six that evening Gordon Stirling presented himself on board the torpedo-boat destroyer Boxer, lying alongside Sheerness Dockyard. Three hours later the permission of the Dutch Government for the British warship to enter Delfzyl was obtained, and at six the following morning she slipped quietly past the Garrison Fort en route for Holland.

"Do you anticipate any trouble with the German destroyer?" asked Stirling, in the course of conversation with the lieutenant-commander of the Boxer.

"No, worse luck!" replied Lieutenant Mallet. "I wish the blighters would fight. Of course this is not for publication, but I can assure you that there's hardly an officer or man in the British Navy who is not as keen as mustard on the question of smashing the Teutons. It's got to come, mark my words, and the longer the delay the harder the job will be."

"My private opinion is this," said the lieutenant-commander slowly: "Hamerton is as much alive as I am. For some reason, inexplicable as far as we are concerned, the Germans are concealing his identity and that of his friend Detroit. That's the opinion of almost every thinking man, woman, and child in the British Empire and in the United States. And yet, what is the result of the joint Ambassadors' Note? Dust in their eyes. And the worst part about the whole business is that the affairs of state are in the hands of a few weak-kneed, peace-at-any-price individuals, who believe that the German is our best friend. I suppose I've said more than I ought; but, hang it! a fellow cannot always keep his feelings bottled up. You're going back with the yacht, I presume?" he added.

"Yes; I am expecting to get another 'scoop'—some startling news—but it looks like a fizzle out."

"If I could have my way I would put you ashore at Harlingen. You could easily get to Delfzyl by train. Then you could assist Smith in working the yacht out to sea, and we would be cruising about ready to drop on S174 should she try any of her little tricks. Then you might have a 'scoop'. But orders are orders, and one-eyed Nelsons who could deliberately ignore signals are not to be found in the navy of to-day."

"The Frisian Islands," remarked the lieutenant as he made his way to the bridge. "Another two hours will bring us within sight of Rottum—that's the Dutch island nearest to the German island of Borkum. We'll go a little way out of the direct course and let our friend S174 know that there is such a thing as a White Ensign."

"Is that Borkum?" asked Stirling of the sub-lieutenant, pointing to a low-lying island, apparently occupied by a few cottages on the side and a row of sandhills.

"Aye; looks harmless enough. Tucked away on the lee side of those dunes is a regular hornet's nest of torpedo craft. Batteries, too, everywhere, and jolly well masked."

"Don't you think it somewhat remarkable that a destroyer should be sent from Heligoland to watch the movements of my friend's yacht when Borkum is so much nearer?"

"I do; but questions have been asked and have been answered—after a fashion. The powers that be seem satisfied, and we have to accept the situation. It's galling, but——"

And with a deprecatory movement of his hand the sub-lieutenant hurried off to join his chief on the bridge.

"Ting-ting!" The bridge telegraph signalled to the engine-room for half-speed ahead. The Boxer was nearing the shoals outlying the Frisian Islands.

"There she is!" exclaimed Mallet, removing his binoculars from his eyes and pointing almost dead over the bows. "That's S174."

The German destroyer was heading straight for the Boxer. In a very few minutes the two craft would be passing each other unless the German boat altered her course considerably.

In obedience to a sign from the lieutenant-commander, a seaman made his way aft to where the White Ensign floated proudly in the breeze. Uncleating the halyards he waited.

"Port your helm," came the order. Mallet, though loath to give way, was resolved to take no risks of collision. As the British destroyer swung away a point to starboard the German followed suit; then resuming their former course the two vessels swept past each other at a difference in speed of quite thirty-eight knots.

Slowly, almost defiantly, the Black Cross Ensign of S174 was lowered and quickly rehoisted. The compliment was smartly returned by the Boxer, and ere her White Ensign was hauled up to the truck the German vessel was observed to be circling to starboard.

"What's her game?" asked Mallet indignantly. "Surely she isn't going to follow us? At any rate she won't overhaul us if I can help it."

The lieutenant-commander's hand was on the bridge telegraph, ready to give the order for full-speed ahead, when the German destroyer shaped a course to the nor'-west. Her commander realized that his attempt to recapture the Diomeda by a ruse or otherwise was a failure. Rather than see the yacht leave the Dollart under the convoy of a British warship he preferred to return to Heligoland.

Since the Boxer's visit to Delfzyl was entirely of a private character there was no official welcome by the burgomaster. Nevertheless all the town seemed to congregate on the quay to await the British destroyer's arrival.

Smartly the Boxer came alongside, and without the loss of so much as a square inch of paint was soon moored to the jetty.

"Ready, Mr. Smith?" asked Mallet, after Stirling had duly introduced the skipper of the Diomeda to the lieutenant-commander of the destroyer. "Good! we'll get out a hawser at once. The tide won't serve us much longer. The sooner we start the better, for, unless I am very much mistaken, there's heavy weather knocking about within fifty miles of us."

Octavius Smith had, in fact, already made all preparations for the Diomeda's departure. As soon as he had received a communication from the Admiralty, acquainting him of the special visit of a British destroyer to tow the yacht back to Lowestoft, he obtained his clearance papers at the Custom House, reprovisioned the craft, and stowed away or securely lashed on deck every article that might otherwise be swept overboard or damaged down below.

"What's the game, old man?" he asked of Stirling, as the latter returned with him to the yacht. "It seems a queer thing to do to send a destroyer solely for the purpose of towing us home. Of course I'm jolly glad, although I enjoyed my detention at Delfzyl. At the same time the letter from the Admiralty is so emphatic on the point that the yacht must be brought home that I can't help fancying that there's more in this than meets the eye."

"There I cannot help you," replied Stirling. "For one thing, I know our friend S174 has cleared off. You received those papers I sent you safely?"

"Oh yes—thanks awfully! It was a rotten climb down on the part of the British and American authorities at Berlin, but I'm inclined to think they are lying low about something."

"I hope they are," agreed Stirling. "By the by, how have you been getting on since I left you in the lurch?"

"Can't complain," drawled the skipper of the Diomeda. "Business fairly brisk; sent off four instalments of those idiotic 'Heart-to-heart Chats' and answered a regular batch of queries from love-sick servant girls. And—funny thing—old Dangler wrote and asked me to contribute a series of articles on 'Art in the Home'. Of course I started the wretched things, but as I couldn't get hold of any copies of London furniture manufacturers' catalogues I was a bit hung up. You can't get inspirations on 'Art in the Home' when you're cooped up in this dog-box of a cabin, can you? They'll have to wait till I get back. But there's the hawser coming aboard."

It did not take long to get the six-inch hawser from the Boxer to the Diomeda, where the end was bent round the yacht's mainmast close to the deck and securely stopped to the gammoning-iron. The bowsprit had already been run in, so as not to have the risk of its being snapped off by the tow rope in the broken waters of the North Sea.

The ropes that held the Diomeda to the quay were cast off, the destroyer's propellers began to churn twin columns of white foam, and the hawser slowly tautened.

As the Boxer and her tow glided away from the wharf the usually phlegmatic Dutchmen raised a cheer, which compliment Smith and Stirling returned by raising their caps. Then, with the speed increased to ten knots, the Diomeda followed in the wake of the British destroyer, homeward bound. As soon as the two craft were outside the Dollart the scope of the towing hawser was considerably increased. Nevertheless the Diomeda pitched and strained in a manner that caused Smith grave misgivings.

Although there was little wind there was a long, heavy swell that presaged a strong breeze, if not a gale, before many hours had passed.

At sunset Smith placed the red and green navigation lights in position, satisfied himself that the hawser was not being chafed by the stemhead, and, having given the tiller into his companion's charge, went below to prepare supper.

"Blessed if I can stick down below," he remarked. "I never felt so much like being seasick in my life. The motion is too rotten for words. It will mean an all-night watch on deck. Of course if you care to go below you can."

"Thanks, I'd rather not," replied Stirling, realizing that he stood little chance against the attacks of mal de mer when Smith had been forced to admit defeat.

"Very well. I'll hand up the oilskins. There's a stiff breeze piping up already."

With alarming rapidity the wind increased, blowing two points abaft the beam to starboard. At midnight it was half a gale. In spite of the speed of the towed yacht crested waves repeatedly broke inboard, till the cockpit was frequently filled with water almost to the level of the seat on the port side.

"Hang on to that lamp," shouted Smith, who had taken Stirling's place at the helm. "We may want it. I wish they would slow down; this pace is a jolly sight too hot."

His comrade was just in time to lift the signalling lamp from a bracket on the after side of the bulkhead when a vicious sea poured inboard. The stem dipped, then, jerked forward by the strain of the towrope, the yacht plunged her bows under till there was solid water as far aft as the mainmast. Just then the hawser parted like a piece of pack-thread, and the Diomeda was drifting helplessly under bare poles in the midst of the angry sea.

CHAPTER XXI

Good Old Hamerton!

Smith's first act was to put the helm hard down, but so fierce was the wind and so stunning the blows of the steep, crested waves that the yacht soon lost way. She wallowed sluggishly in the trough of the sea, cascades of water pouring over her on all sides. A crash, just audible above the roar of the elements, announced that one of the panes of the cabin skylight had been broken.

There was no time to reef the sail. Staggering upon the wedge-shaped part of the deck abaft the mizen-mast, Smith tore frantically at the sail-tyers, while the boom charged to and fro with the force of a sledge-hammer as far as the scope of the sheet permitted.

Flapping with a series of whip-like cracks the stout canvas was hoisted. The men expected every moment to see the sail split asunder and the mast go bodily over the side. It was with feelings of relief that they saw the sorely pressed craft swing round head to wind without the threatened calamities taking place.

As he spoke a searchlight flashed out of the darkness. For a few moments it swung in a more or less horizontal direction, as far as the erratic motion of the destroyer permitted; but as soon as the beam fell upon the Diomeda the light was immediately screened.

Again the searchlight threw out its rays, and to the astonishment of both men they saw revealed the British destroyer less than a quarter of a mile away. In the brilliant light the Boxer could be seen plugging her bows into the vicious waves. The spindrift was flying high over her four squat funnels, cascades of foam were pouring from her fo'c'sle deck, while, owing to the greatly reduced speed, she was rolling like a barrel.

Then the mysterious searchlight vanished, leaving Smith and his comrade blinking in the darkness.

"Hanged if I know and hanged if I care," replied Smith. "Where's that lamp? There's the Boxer signalling."

Throughout the whole of the hazardous period the flashing lamp in the cockpit was still intact. Bracing himself against the swaying mizen-mast the skipper of the Diomeda replied by a few short flashes.

Slowly and deliberately the message was flashed from the destroyer, for the naval men knew that the average yachtsman is more or less of a duffer at Morse signalling.

"Ride to sea-anchor if you have one. Keep your lights burning; traffic about. Will stand by you."

"I understand," was Smith's reply, after the message had been roughly jotted down and transcribed by the aid of a codebook.

Within ten minutes the yacht was riding to her sea-anchor. The motion, as compared with the straining and plunging while under tow, was fairly easy, and after lashing an awning over the broken skylight the crew of the Diomeda were able to "stand easy".

"But I did. Don't you remember my saying something about being hanged if I cared, when you asked me what vessel that was that was flashing her searchlight?"

"After all, it was a silly question," rejoined Stirling. "How could you be expected to know any more than I should?"

"I believe I do know, though," asserted Smith. "Look away on our port hand. Do you see those patches of misty light on the sky?"

"They're searchlights playing on the clouds. Evidently the Heligoland torpedo flotilla are engaged in night manoeuvres; to me it seems like a trial of aircraft versus submarines and destroyers."

"And the vessel that turned her searchlight on the Boxer? She wasn't sky hunting?"

"No; not just then. You see, she spotted the navigation lights of the Boxer and the Diomeda, and was naturally curious. But there she goes!" As Smith spoke a narrow ray of light flashed vertically upwards at apparently less than two miles away to the southward. Then, describing an ever-widening spiral, the beam searched the clouds for a considerable time, till, having satisfied herself that the object which she was in search of was not within range of the searchlight, the foreign warship screened the light and made off.

"Let's get below; it's fairly habitable," suggested Stirling. "I'm mighty hungry; and even these oilskins seem to strike cold."

"Very well; you go," was the reply. "I'll stick here till daybreak. It can't be much longer, and I fancy the wind is dropping a lot."

"It is, but it was thick while it lasted. We must have struck the tail-end of a summer hurricane." With that Stirling went below, divested himself of his oilskins, and proceeded to mop up the salt water from the cabin floor. This done he made coffee, handing out a cup to his comrade in the cockpit.

"Dawn's breaking; seas going down rapidly," replied the skipper optimistically. "The searchlights haven't been showing for the best part of half an hour."

"Rather. I can just see her outlines against the sky. It will be quite light in twenty minutes."

As soon as the grey light in the north-eastern sky was strong enough to enable things to be seen with sufficient clearness the Boxer bore up to leeward of the yacht. By means of a megaphone the lieutenant-commander shouted to Smith to get the sea-anchor aboard, and prepare to be taken in tow.

This, by reason of the sea that was still running fairly high, was a difficult task, and by the time the yacht was again wallowing astern of the destroyer it was a quarter to five.

For the next two hours good progress was made. Almost momentarily the waves grew calmer, so that the Boxer was able without undue risk to her charge to increase speed to twelve knots. Never before had the stanch old yacht travelled at that rate. Her following wave was a sight to behold, towering and threatening to break inboard over her pointed stern, yet never able to overtake her. After the night of anxiety both men found the motion most exhilarating, and there was every chance of sighting Old England's shores well before noon.

Suddenly Stirling grasped his companion's arm, then pointed to an object well above the skyline on the starboard bow.

With some difficulty, owing to the motion of the yacht, the skipper got the glass to bear.

"I don't think so. The British ones show a dull yellow or light brown with the sun shining on them. This chap's a peculiar shade of grey. I'll semaphore to the Boxer and ask if they've spotted her."

But before Smith could get the two hand-flags from the signal locker the destroyer's gunner, followed by three seamen, came running aft.

Steadying himself by the wire rail, the warrant-officer raised a megaphone to his lips.

"We're going to cast you adrift,"' he shouted. "Make sail and steer sou'-sou'-west. There's a foreign airship in difficulties. We're off to investigate. Will return and pick you up later."

The gunner shook his head and tapped the megaphone suggestively. Without its aid conversation was inaudible.

Hardly had Smith cast off the hawser and the crew of the Boxer gathered it aboard when the destroyer set off at full speed in order to intercept the drifting airship.

Having set staysail, jib, and mizen, the skipper of the Diomeda shaped a course as indicated by the Boxer, while Smith's telescope was brought into constant use by one or the other of the crew.

"She's descending," announced Stirling. "By Jove, she'll fall into the sea in a minute—no, she's steady. They have evidently emptied the water-ballast tanks. Here, you take the telescope."

The Boxer had apparently come within the proper distance of the airship, for although it was almost an impossibility to gauge relative distances through a telescope, Stirling could see the destroyer circling to starboard.

"They've got a line on board," he declared excitedly. "The airship is turning head to wind. The Boxer is returning. I say, what luck for the Westminster Daily Record! 'Exciting salvage of a Zeppelin by a British destroyer in the North Sea—by our Special Correspondent.' How will that look?"

"I shall be able to look the better if you'll kindly hand me the telescope," said Smith grimly. "Thanks! I am a rotter though. If I had only had the forethought to bring a camera—can't be helped. She's badly damaged, I can see. No one on board. Yes, there is, by Jove. There's a fellow in a greatcoat standing just in front of the midship car, or whatever they call it."

Nearer and nearer came the destroyer, with the Zeppelin straining and seesawing at the end of a hawser against the fairly stiff breeze. Presently the semaphore on the Boxer's bridge began to work.

As soon as Smith made the acknowledgment he seized a pencil and jotted down the movements of the signal arms; then by the aid of a diagram in the signal book he deciphered the message.

"Carry on under sail. Cannot take you in tow. Have sent by wireless to Harwich for assistance."

"I understand," replied the Diomeda's skipper by semaphore; then taking up the telescope he directed it towards the airship.

The Zeppelin was now less than half a mile off. By the aid of the glass Smith could see the solitary figure on the suspended platform.

"Hurrah!" shouted Stirling. "Now what price the German Government's explanations? And, old man, what a scoop! The Westminster first, the rest nowhere. Good Old Hamerton!"

CHAPTER XXII

A Momentous Decision

At a quarter to five in the afternoon of the same day as the salvage of the derelict Zeppelin was effected, Rex Thompson, the energetic editor of The Westminster Daily Record, was superintending the final setting-up of the evening edition.

The stop-press column was being delayed until the tape machine had finished the report of the strange occurrence in the North Sea—how a British destroyer had fallen in with and had towed into Harwich one of the latest type of Zeppelins. Presently the door was flung wide open, and Gordon Stirling burst into the room.

"Hallo, where did you spring from?" demanded Thompson in even tones. "I thought you were supposed to be in Holland?"

Stirling's face fell. It seemed hard lines, after having received Lieutenant Mallet's assurance that no information would be given to the Press representatives of Hamerton's presence on the fugitive airship, that the news should have leaked out. The knowledge that a German airship had been brought into Harwich was common property. It was impossible to hide a gasbag of nearly a million cubic feet capacity from the public gaze, but Stirling counted on Mallet's word. The details were, of course, communicated by wireless to the Admiralty, but The Westminster Record's special was to be the medium whereby the news of Hamerton's hairbreadth escape was to be given out to the great British Public.

Stirling dare not telegraph or telephone the momentous news. Instead he chartered a powerful car, and in an hour and twenty-five minutes the chauffeur drew up outside The Westminster Record's offices.

And then came the crowning disappointment. In bland tones he had been informed by his chief that the news he brought was a trifle—just a trifle—late.

"You might, however, glance at this," continued Thompson, handing him the typed transcript of the tape message. "If there's anything important to add, let me know."

The editor, mentally burying himself in a mass of papers, was suddenly startled by a tremendous crash. Stirling had, in his excitement, brought his fist down heavily upon the table, causing Thompson's fountain pen to splutter all over a nearly completed leader, while the pastepot and a bottle of red ink indiscriminately shed their contents over the latest efforts on the part of The Westminster Record's parliamentary representative.

Thompson was on the point of using language that could hardly be termed parliamentary, even in these latter days of politics, when Stirling interrupted him.

"You haven't got it," he shouted, almost carried away in his excitement. "You've missed the whole point. Hamerton's back!"

"Silly owl; you've missed the chance of a life-time. Carry on. Scribble half a dozen sticks—no, half a column. I'll get the space held open."

Stirling was perfectly collected by this time. He wrote as he had never written before—at great speed, yet in a lucid, connected style.

Thompson seized the blue pencil in anticipation. A look of mild satisfaction that quickly gave way to exuberant delight overspread his face as he read. The blue pencil was not required.

"Well done, Stirling; a straightforward piece of work, and every line full of life!" he exclaimed, betraying an unwonted enthusiasm. "Now, take my advice: go and get a good square meal, and go to bed early. There'll be nothing doing, as far as you are concerned, till to-morrow morning."

Meanwhile Sub-Lieutenant Hamerton, temporarily "rigged out" in mufti obligingly lent by the commander of the Boxer, quietly slipped ashore at Harwich, took train to town, and with the least possible delay reported himself at the Admiralty.

For over two hours he was detained by the First Lord and the First Sea Lord, both of whom happened by a pure slice of luck to be in Whitehall when the momentous cipher telegram announcing Hamerton's return in the disabled Zeppelin was received.

"There's an underhand piece of work somewhere," remarked Admiral Sir James Churcher, the First Sea Lord. "Coming on the top of the German Government's explanation to our ambassador it cannot be regarded as otherwise."

"I agree with you," said the First Lord. "This affair will ultimately be settled by the Navy, Churcher, of that I feel sure."

"She won't; it will be a hard fight to the finish. These Teutons are of very much the same characteristics as ourselves, remember. Of course, diplomatic negotiations may put off the evil day, but after the way our Foreign Office has been utterly fooled I don't put much faith in that prospect. By the by, Mr. Hamerton, you mentioned that you found a German confidential book on torpedoes. What became of it?"

"I hardly know, sir. It seemed as if they had made up their minds to condemn us long before the actual trial."

"Unfortunate," remarked Admiral Churcher. "The range of the new-pattern Schwartz-Kopff torpedo is considerably greater than that of our improved Whitehead. There is a rumour—we cannot obtain confirmation—that its maximum range is twelve miles. It all depends upon the motive power. Of course this is an important advantage, so far as Germany is concerned, and it is a great pity that we failed to obtain the secret, once the book was in your possession, Mr. Hamerton. I realize, however, that it was due to no fault of yours."

"I congratulate you once again," continued the First Sea Lord, "on your escape. For the next two days you ought to rest, but I fear the exigencies of the Service will not permit. So be prepared to find your appointment posted in the course of forty-eight hours or so."

The Sub took his leave. In the anteroom he rejoined his father, who, on receipt of a telegram, had hastened to meet his son; and the two made their way towards the main entrance.

"Here is Mr. Hamerton," said the uniformed messenger, addressing a short, thick-set individual, whose face bore a smile of anticipated pleasure.

"Glad to meet you, Mr. Stirling," said the Sub warmly. "I know who you are now, right enough. You're the fellow who discovered that Detroit and I were prisoners on the island of Heligoland."

"Didn't do much good, I'm afraid," added Stirling modestly. "You got away independent of that. But this is what I want to see you about," holding out a small paper parcel. "I found it stowed away on the Diomeda. It's a torpedo book."

"You did, by Jove!" exclaimed Hamerton. "Stirling, you have done a national service. I thought the book had been found by the German officer who searched the yacht. Stand by in the waiting-room for a few minutes longer, Pater; I'm going to take Mr. Stirling in to see the First Lord."

It would be no exaggeration to affirm that the whole of the English-speaking inhabitants of the globe were agitated by the astounding escape of Sub-Lieutenant Hamerton from captivity.

In America anti-German sentiments rose high, while urgent representations were made to the Capitol that an emphatic demand for Detroit's release should be instantly sent to Berlin.

Both in Great Britain and the United States it was realized that an international crisis was imminent. Consols dropped lower than they had ever been known to fall before. The American Pacific Fleet was ordered to pass through the Panama Canal and join the Atlantic Squadron at a rendezvous off Cape Hatteras, and await orders. Simultaneously the British Fleet, that for years past had been placed on a war footing, was unostentatiously mobilized; the Portsmouth, Portland, and Devonport ships being ordered to concentrate at the Nore, while the Third and Fourth Squadrons of the Home Fleet were sent to Cromarty Firth.

For the present nothing more could be done without indirectly challenging Germany to settle the matter by the arbitrament of war. Diplomatic relations were yet to be given one more chance, in the hope of allaying the enmity between the great rivals for sea supremacy.

General Heinrich von Wittelsbach had been once more hurriedly summoned to Berlin. With a heavy heart he set out to meet his imperial master. Fate had indeed treated him badly, though no less than his high-handed actions—done, according to his views, in the interest of the Fatherland—demanded. Not only had he failed to keep one of the alleged spies under lock and key; he was threatened with ignominy. It seemed impossible for him to explain satisfactorily the reason for deceiving the Emperor, who, on his assurances, had imperiously replied to the British and American Ambassadors' Note. There was also the humiliation of having lost one of the latest Zeppelins, which Great Britain was keeping under the pretext that it was unfit to be towed back to Heligoland, but in reality as a hostage.

"General, you have been over-hasty," was the Emperor's greeting, "I might say over-zealous."

"One moment, Von Wittelsbach," said his Imperial sovereign. "Before you start offering regrets would it not be better to give us your version of this affair—the true version, mind? What say you, Von Rhule?"

Von Rhule, the Chancellor, who was the only person present at the interview, merely inclined his head. He was a man of few words, but he had a will of which even his master stood in awe. His policy was not only "Germany for the Germans", not merely a desire for "a place in the sun", but a determination to make the German Empire the predominant nation on land and sea. Although his rise to power had been of comparatively recent date, he was beginning to be recognized as a super-Bismarck. If Bismarck were described as a man of blood and iron, Von Rhule's ambition was to be regarded as a man of brains and steel. Needless to say, he was an Anglophobe. One of the few disappointments of his hitherto brief career was the failure of his agents to provoke a quarrel between the United States and Great Britain over Mexican affairs. He placed very little reliance upon the Triple Alliance. His idea was to set Austria against Russia and engineer a war between France and Italy. Germany, standing aloof during the struggle between the two pairs of combatants, could then afford to dictate to the victors of the exhausting war.

Heinrich von Wittelsbach had the acumen to perceive that the Emperor was inclined to treat the Hamerton and Detroit incident in an indulgent way. In a blunt, soldier-like fashion the commandant of the garrison of Heligoland told his story, omitting no important point and offering no excuses.

"Sire, my motive was simply the great desire of my career: to safeguard the output of the Empire against all attempts on the part of foreign powers to steal the results of patience and diligence on the part of the German nation. I have freely admitted that my initial act in hastily placing those men under arrest was an error."

"And therefore you hoped, by piling error upon error, to remedy your original fault?"

"And have placed me in a quandary. Germany must either become the laughing-stock of the whole world or else command respect at the point of the sword. Look at the present state of this affair. The English are clamouring for war. History will tell you that their ancestors demanded and obtained a declaration of hostilities against Spain simply on account of the loss of a man's ear. I know them; they are a peculiar nation. Their ministers of state are ever proclaiming their desire for peaceable relations with us; yet, in spite of their vaunted boast to act fairly and squarely with all the world, they would deny us the right to develop as a healthy nation ought and must. Am I not right, Von Rhule?"

The Emperor's brow darkened. He remembered the incident only too well. A few months ago two Alsatian recruits had been drafted with others to German South Africa. The men, bullied and ill-treated by their officers, deserted and escaped into Walfisch Bay. The German officer in command dispatched troops in pursuit, and the latter, possibly unwittingly, entered British territory. A native, refusing to give information, was ordered to be beaten, and in retaliation a number of Kroomen stoned the German soldiers. Meanwhile the British authorities refused to give up the deserters on the grounds that they were political refugees, and ordered them to be sent on to Cape Town.

For a few moments the Emperor looked fixedly at the Chancellor, then in low, emotional tones he asked:

"Stop!" exclaimed the Emperor. "Was not a similar reply given to the Emperor of the French half a century ago? You know what that led to? Have we the Reichstag solidly at our backs?"

"All, sire, except the Socialists on the extreme left. But they need not be taken into account. Later on they will be dealt with as their stubbornness merits."

"Then there is the possibility, nay, probability, of a rupture with the United States?"

"True, sire; but give us four clear days and Great Britain will be humiliated; her navy will be almost utterly destroyed. Our destroyer flotillas could then lie in wait for the American fleet, and it will be a case of Tsuhsima over again."

"Assuredly, sire. Everything is in our favour. Take the English fleet at the present time. Nine battleships and battle-cruisers are under repair in the various dockyards, eleven battleships and their attached craft are now in the Mediterranean, eight days' steaming from the Straits of Dover. Thus we have a predominance in battleships in the North Sea, to say nothing of the surprise attack our destroyers and submarines are able to deliver. Our aerial fleet also——"

"True, sire, but an aerial fleet will be able to inflict enormous damage to the docks of the east coast of England; perhaps even London may be reduced to a heap of ruins."

"There is no need to make allowances for chance, sire. Our preparations are made so as to be independent of that."

"Sire," he continued, "never again will such an opportunity present itself. By next year these English will have five new battleships in commission, without counting four built for foreign Governments and which they can press into their service. Thanks to our friends the Socialists on the extreme left, our expenditure is limited to the construction of only three large ships of war. The people are groaning under the imposts: it will be unwise to press them by additional taxation. Our destiny lies on the sea. You, sire, know it well. Throw away the chance of achieving our dominant end, and never again will a like opportunity present itself."

"So be it," concluded the Emperor. "We will summon a meeting of the Supreme War Council this afternoon."

CHAPTER XXIII

First Blood

Without the formality of a declaration of war hostilities were begun. Taking the precedent of the Russo-Japanese war, when the Japs delivered what might be termed a treacherous attack upon Port Arthur—an act that was tolerantly regarded by her ally, Great Britain—a squadron of Zeppelins, numbering seventeen in all, proceeded to a rendezvous at the mouth of the Elbe, accompanied by seventy-two seaplanes. As night fell the whole of the destroyer flotillas of Heligoland, Borkum, and Westerland Sylt shaped a course for British waters. Two hours later the aircraft left to deliver simultaneous surprise attacks upon Sheerness, Harwich, the Tyne, Rosyth, and Dundee.

At midnight the British and American ambassadors at Berlin were informed of the outbreak of hostilities. Guards were posted outside the embassies, and all telephonic and telegraphic communications from these buildings were interrupted. The ambassadors were informed that they would be at liberty to leave Germany either via Paris or Vienna after a lapse of twelve hours.

At 2 a.m. the cables between Borkum and Lowestoft, which, subject to censorship, had been working normally, suddenly ceased to transmit messages. From that moment all direct telegraphic communication between Great Britain and Germany was broken off.

Strangely enough, that very element of chance that the German Chancellor claimed to have eliminated became most pronounced. For weeks past the prevailing winds had been from an easterly or north-easterly direction; now without warning they backed to the westward. By midnight it was blowing with almost the velocity of a hurricane. Consequently the German aircraft, especially the Zeppelins, made a comparatively slow voyage.

Now it happened that the British fishery-protection gunboat Onyx was cruising off the sou'-west tail of the Dogger Bank, and the attention of the officer of the watch was called to a peculiar buzzing sound overhead that was plainly audible during a lull in the wind.

Bringing his night glasses to bear the officer made the discovery that a number of seaplanes were battling against the wind, their direction being due west.

Fortunately the lieutenant did not attempt to train a searchlight upon the aircraft, nor did he offer to enter into communication by means of a flashing-lamp; but he promptly got in touch with Scarborough wireless station:—

"From Onyx, lat. 54° 17' 20" N., long. 2° 9' 30" E. Sighted seaplanes, numerous, nationality unknown, steering due west."

With commendable promptitude this information was transmitted to the Admirality, and since it was known that none of the British seaplanes had left their respective bases that night, it was taken for granted the aircraft were of German nationality. Orders were immediately given for the east-coast defences to be on the qui vive, and for the Nore, Harwich, Rosyth, and Dundee flotillas of destroyers and submarines to put to sea.

Dawn was just breaking when the belated German seaplanes came in sight of the leading British vidette boats from Harwich. The aircraft, battling against the furious wind, were rocking and pitching so much that the attention of their pilots was directed towards the maintenance of stability.

Presently one of the German seaplanes dropped a bomb. It exploded harmlessly at a distance of more than two hundred yards from the British destroyer Lynx.

From that moment all doubts as to the intentions of the aerial fleet were set at rest. The destroyers instantly opened fire, and, in spite of the high seas that were running, made excellent results. Whether the seaplanes were two hundred or two thousand feet in the air their destruction was no less certain; few could resist the explosion of the highly charged shrapnel. It was, to use the words of a first-class petty officer, "like knocking over a lot of partridges".

In ten minutes the few aircraft that still escaped damage turned tail and fled before the wind.

The seaplanes detailed to operate on the Scottish coasts fared no better, but in the case of those operating against the Tyne ports a small success fell to their share, though more by accident than by design.

Within recent years powerful batteries had been erected at Cullercoats, Tynemouth, North Shields, and Frenchman's Bay for the defence of the Tyne, and at Roker and Hendon Hill for the protection of Sunderland. These either superseded the previously ill-armed batteries or were on entirely new sites. For purposes of mobilization they were entrusted to the Tynemouth Territorials of the Royal Garrison Artillery, who held the honour of being first in precedence of all the several groups of this branch of the Service.

Upon the hasty though not unexpected order for mobilization these men nobly responded to the call. Many of them, summoned from their work in the great shipbuilding yards, had no time to don their uniforms, but they could shoot none the worse on that account.

At exactly a quarter past four, just as the sun was breaking above a bank of clouds, the first hostile seaplane was sighted by the gunners of the Cullercoats Battery.

The German airmen had already realized that, owing to the climatic conditions, all attempt to deliver a surprise attack was hopeless. But their orders were definite. There was to be no turning back.

To a certain extent their method of attack was better planned than those of their ill-fated detachments, who were already either destroyed or in full flight. They flew high and with a great space between the pairs of units. Moreover, with the sun well behind them, they offered a difficult target to the British gunners.

The nearest hostile seaplane was actually immediately above the lighthouse at the end of the North Pier of Tynemouth harbour when a twelve-pounder shell from the Cullercoats Battery struck her. In the twinkling of an eye the graceful bird-like machine was literally blown to atoms, the explosion of her petrol tanks throwing out spurts of lurid flame out of which fragments of the ill-fated craft fell with unequal velocity into the sea.

Undeterred by this catastrophe, the second aeroplane, travelling through the air at a rate of seventy miles an hour, passed over the South Pier. Several times she swayed ominously in the air currents set up by the projectiles which screeched within a few feet of the swiftly-moving target.

Now she was within the line of batteries and immediately above the most congested quarter of South Shields. It seemed as if nothing could prevent the seaplane from working havoc upon the crowded shipping between Tynemouth and Newcastle. Men, women, and children crowded into the streets, gazing in blank astonishment at the sight of a hostile aircraft making ready for its work of destruction. Tales of probable invasion had for years past fallen upon deaf ears; now that the actual danger was apparent they could not realize it.

They were not long left in doubt. The seaplane slowed down, and, descending to less than four hundred feet, dropped two bombs in quick succession. No doubt these were intended for the petroleum tanks owned by the Tyne Commissioners. Both missiles went wide of the mark. The first struck and destroyed a Russian timber barque moored at the jetty; the second demolished the best part of a row of houses, and started a disastrous fire that, before it was extinguished, laid bare nearly an eighth of South Shields.

Following the course of the river the seaplane flew onwards. Four hundred feet beneath her lay the locks of Tyne dock, the great commercial basin controlled by the North-Eastern Railway Company, and which, in time of war, would form the principal coaling and oil-fuel base for British destroyers obliged to replenish their bunkers and tanks in the Tyne.

At this juncture two companies of the 7th Battalion of the Durham Light Infantry were on their way from their drill hall. Luckily they were armed and provided with ball ammunition, and without hesitation the officer in command ordered them to open fire. It was realized that the danger of the bullets falling to earth was less than the peril from the bombs of the modern terror of the skies. Soon the sharp crackle of musketry began.

Several times the seaplane was struck, but without serious result, till without warning one of her wings appeared to crumple up. Round and round spun the stricken craft, dropping rapidly towards the ground, with her propellers still buzzing at a furious rate. "Cease fire!" came the order, and with bated breath the Territorials watched the result of their work.

Presently the downward fall was retarded. One of the crew of the seaplane had released the umbrella-like parachute. Nose downwards the stricken craft continued to plunge; only by means of leathern straps were the ill-fated Germans prevented from being thrown clear of the wreckage.

Ever so slowly it seemed to the watchers did the seaplane fall, till, with a dull crash, the framework struck an open space between the dock office and the buildings of the chemical works.

The crash was instantly followed by the petrol taking fire, while above the hiss of the flames could be heard the shrieks of the luckless Germans who were unable to disentangle themselves from the wreckage.

No longer were they looked upon as enemies; they were human beings in peril. The "Terriers", dropping their rifles, began to run to the aid of the burning airmen, but before the foremost got within a hundred yards of the wreckage a tremendous explosion sent most of the men over like ninepins. The remaining bombs that had survived the impact of the fall had exploded, and when the would-be rescuers approached the scene of the disaster they found a hole nearly twenty feet in diameter and six feet deep blown out of the ground.

Another seaplane, winged by the gunners of the Spanish battery—where two seven-pounders of a modern type had only recently been mounted—fell into the sea off Freestone Point. Her crew were promptly rescued and captured by the coastguards, and the damaged seaplane was dragged ashore in triumph.

As for the other hostile aircraft menacing the Tyne ports, not one came near enough to make use of its powerful means of offence. Many were destroyed; the rest, realizing the hopelessness of the task, turned and flew towards the coast of Germany.

Five of the latter succeeded in entering the Firth of Forth, but none got within striking distance of the four British super-Dreadnoughts lying with steam up off Rosyth. The vigilant swift third-class cruisers attached to that base quickly settled the destroyers as they pitched and plunged against the steep seas off the Bass Rock.

In every other case the detachments of the German destroyers were met and overmatched by the superior numbers and greater seaworthiness of the British craft. Had the German seaplanes rallied and supported their destroyers during the hot conflict that ensued the result might have been different. But they did not. Once more, as in times past, the elements came to the aid of Great Britain. The surprise attacks had signally failed. It was now left to the British Navy to seek out the German battleships, and once and for all to settle the question of supremacy on the high seas.

CHAPTER XXIV

The Battle of the Galloper Sands

At 9 a.m. on the same morning as the surprise attack by the German "mosquito craft", two squadrons of the First Home Fleet left the Nore. The flag of the Commander-in-chief, Admiral Sir Noel Armitage, was flown on the Royal Sovereign, one of the latest type of super-Dreadnoughts, a vessel mounting eight fifteen-inch guns on the centre line and a secondary armament of sixteen six-inch guns.

It was Sir Noel's plan to bring the German High Seas fleet to action, and should, as he devoutly hoped, the British be victorious, a general attack upon Borkum and Heligoland would follow. It was on account of his knowledge of the latter fortress that Sub-Lieutenant John Hamerton was appointed to the Royal Sovereign as a supernumerary.

The heavy sea had somewhat subsided, although there was a long roll that is rarely met with in the North Sea. The wind, too, had dropped considerably as the sun rose, but the atmosphere was thick and hazy, so that it was impossible to detect a vessel more than a mile off.

Although not so bad as a sea-fog, the climatic conditions made all fleet evolutions a kind of exaggerated blindman's buff. The light cruisers and destroyers, spread out fanwise for several miles ahead of the battleships, could hardly live up to their reputation as the "eyes of the fleet", since it was only by stumbling across one of their antagonists that they could detect their presence.

Under these circumstances Sir Noel wisely decided to remain within easy distance of the mouth of the Thames. By proceeding far from his base it would be possible that the German battleships and battle-cruisers might slip past unseen and do enormous damage to the East Coast before he could offer them battle. Every hour meant the shorter distance between him and the Mediterranean Fleet, that, hastily summoned by wireless, was pelting along at twenty-two knots from Gibraltar.

On the other hand, the Germans were also ignorant of the precise position of their antagonists. They would vastly prefer to fight—now that the initial operations had failed—within easy distance of the mouths of the Elbe and Weser. If the worst came to the worst they could then pass their battleships through the Kaiser Wilhelm Canal into the comparative safety of the Baltic, and rely upon their torpedo craft, submarines, and mines to keep the enemy at bay. But for the present the Germans had no fears on that score. The fighting spirit ran high, and the officers and men of the High Seas Fleet confidently regarded that "The Day" was at hand when British arrogance should receive a fatal blow.

Once again the German officials' plan went awry. Instead of the British giving battle, as they expected, Sir Noel Armitage remained close to the Nore. Not only was the Mediterranean Fleet about to join forces with the Home Fleet, but a powerful United States squadron was on its way from the rendezvous off Cape Hatteras to operate with the British in the North Sea. Thus, before the comparatively weak force under Sir Noel's command could be crushed, there was a possibility of an overwhelming predominance of Anglo-American ships appearing in German waters.

Then it was that the German Admiral, Von Walsdorf, decided to take a bold and risky step. He detached three armoured cruisers and eleven ocean-going destroyers—a force he could ill afford to dispense with—and sent them via the north of the Orkneys to prey upon the shipping and comparatively unprotected ports on the west coast of Great Britain. Once these vessels avoided the British destroyers at Scapa Flow there was little risk of capture, while the moral damage they would be able to inflict would outvie the enormous actual damage done in a very short space of time.

Then, finding the British Fleet, as he thought, inactive, Von Walsdorf led his battleships and the remainder of his armoured cruisers towards the mouth of the Thames.

It was just before noon on the following day that the Royal Sovereign received a wireless from the fast cruiser Beresford announcing that she had sighted the German fleet in lat. 52° 1', long. 2° 50' E., steering south-west. The cruiser had, in fact, been chased and fired upon by two of the enemy's armoured cruisers, but owing to her superior speed she eluded them without sustaining damage.

By means of a code-text message the British admiral satisfied himself that the Beresford's wireless information was authentic. This was necessary, since there was the possibility of the cruiser falling into the enemy's hands and a deluding message being sent by her captors, purporting to come from the British vessel.

Majestically the British fleet advanced, steaming in double columns, line ahead, with the "small fry" on either flank. The ships, cleared for action, looked the very embodiment of latent strength and invulnerability, the only dash of colour about them being the white ensigns fluttering proudly in the breeze, the St. George's crosses of the various admirals, and the occasional hoist of bunting to communicate an order to the various ships.

Hamerton's post was with Sir Noel Armitage in the conning tower, the most vulnerable of the armoured parts of the ship; vulnerable because it is a matter of impossibility for the officer working the ship to be completely shut in. He must be able to see what is going on, and the smallest slit in those massive armoured walls will admit a white-hot sliver of steel from a bursting shell, while the conning tower is the favourite mark for the hostile gunners.

Until the German fleet actually hove in sight Sir Noel preferred to remain with his staff upon the bridge. It was a magnificent sight to look astern and see the double line of steel monsters, leaden-coloured themselves, ploughing through the leaden-coloured water, each vessel following with mathematical precision in the wake of the one next ahead until the rearmost ships were lost in the haze.

Hardly a word was spoken by the officers on the bridge of the flagship. For his part Hamerton felt a peculiar indescribable sensation that caused a dryness of the lips and tongue. It was not fear; it was a kind of conjecture, trying to bring himself to realize that he was going into action for the first time of his life, to participate in the greatest naval battle that the world had yet seen.

Every now and again a messenger would come running up the bridge ladder with a "wireless" report. The admiral and the captain, and perhaps the flag-lieutenant would converse in low tones, generally ending in an expressive shrug of the shoulders. Wireless messages reporting the near approach of the German battleships were arriving with monotonous frequency.

Suddenly a dull roar came from the invisible haze away to the eastward. The protected cruisers and destroyers on the flank of the approaching fleet were hotly engaged.

Giving a final glance at the vessels astern Sir Noel entered the conning tower, followed by the captain, flag-lieutenant, Hamerton, and a midshipman. Already the limited space was occupied by a yeoman of signals and a quartermaster, while at the head of the steel ladder inside the armoured pipe that communicated with the engine-room telegraph and steering-wheel compartment beneath the armoured deck appeared the head and shoulders of another yeoman of signals, whose duty it was to transmit orders should the electrical gear be thrown out of order.

Hamerton could see nothing. The admiral had taken up his stand at the slit commanding a view ahead, the captain and the flag-lieutenant had also appropriated a similar means of outlook. Hamerton and the midshipman were perforce compelled to stand inactive, not knowing what was going on, since no word was spoken by the officers on the look-out.

Presently the Sub saw by the indicator, and also felt, that the flagship was turning to port, an example that was followed by every ship on both sides. The leading vessels of the German fleet had been sighted, and the alteration in course was to enable the whole broadsides of fifteen-inch guns to be brought to bear upon the enemy.

Then with a roar and a concussion that shook the ship the big guns were discharged. Almost immediately came a deafening crash overhead. The Royal Sovereign had received her baptism of fire. A huge shell from the German flagship had struck the roof of the superimposed turret, glanced up, and utterly demolished the bridge. A waft of acrid-smelling smoke drifted into the conning tower, making the occupants cough and splutter like men subject to asthma.

After that the firing became general, each heavy gun being discharged as fast as the automatic rammer could thrust home the giant projectiles and the breechblocks could be closed. Between the deafening roars of the fifteen-inch guns came the quicker, though hardly less ear-splitting reports of the secondary armament—the six-inch guns in various armoured casements on the main deck and other parts of the ship.

All the while came the titanic sledge-hammer blows of the enemy's shells, accompanied by the rending of steel, the crash of falling masses of metal, and—far too frequently—the shrieks of men torn by the fragments of bursting projectiles in spite of the best protection that human ingenuity could provide.

Hamerton felt perfectly calm and collected now. The first blow had banished the burning sensation in his throat, although, did he but know it, his face was streaming with perspiration and streaked with dust from the exploded cordite charges.

Both fleets were now on parallel courses, hammering at each other at less than a mile apart. It is all very well to assert that the modern naval battle will be decided at eight to ten thousand yards range: the atmospheric conditions have to be taken into account, and this battle off Galloper Sands was fought in a haze that is more frequent than otherwise in the North Sea.

All order was now at an end. It was impossible for the ships to keep their stations. Already some were sinking, and others forced to haul out of line owing to serious damage; while there was hardly one of the vessels, which a bare quarter of an hour before were as taut and trim as a naval officer could desire, that looked little better than a mass of floating scrap iron. Almost everything that could be shot away had disappeared before the terrible force of the heavy shells, till it seemed a wonder that a single ship could remain afloat.

Of all this Hamerton saw nothing. He was waiting. It was his duty to wait till ordered to do something.

"See what is wrong with the for'ard starboard six-inch," he said abruptly. The voice tube and electric wires communicating with that particular casemate were long out of action.

Hamerton saluted, and promptly descended the ladder to the deck beneath the waterline. Half a dozen anxious pairs of eyes asked mute questions. The Sub could only shake his head; he knew nothing.

Along a passage beneath the protected steel deck he made his way. Below, the ship appeared in normal condition. Everything below the waterline was practically intact, except that the concussion had broken every electric lamp in the ship, broken glass littering every square foot of space.

It was only by means of this passage and one more that direct means of communication could be maintained from one end of the ship to the other. The Royal Sovereign was built with three longitudinal bulkheads, extending from the keel plates to the upper deck, and completely separating the port engine-room from the starboard. In addition there were numerous transverse bulkheads, in which all watertight doors had been closed at the beginning of the action. Every man on board, save a very few, was encased in a steel box that might prove his tomb.

At the head of the ladder communicating with the main deck Hamerton crept under the flexible-steel splinter net. He was now well above waterline, and in a part of the ship only protected by fairly thin side armour. The space 'tween decks was filled with a pungent, yellowish vapour, pierced here and there by shafts of light that entered by means of huge jagged holes in the ship's side. The deck resembled an ironfounder's store, pieces of bent, twisted, and shattered steel lying in all directions and positions.

Something prompted the Sub to bend his back and run as hard as he could to the door of the casemate. Afterwards he wondered why he did, for had a shell entered and burst just as he was making his way along that part of the deck, stooping down would not have made any difference.

Seizing the gunmetal catch of the armoured door the Sub strove to turn it. Then he became aware that the metal was hot. He placed his hand against the steel door; there the heat was unbearable. Picking up a piece of iron bar Hamerton inserted it in the handle, and by a powerful lever-like motion succeeded in turning the catch. The door flew open, and the Sub leapt backwards, nearly overcome by a blast of hot and fetid air.

One glance was sufficient. A small shell had entered the casemate by the gap between the chase of the gun and the shield, and had exploded, killing every man of the crew of the six-inch. There was no escape. Those who were not slain by the direct explosion were killed by the fragments of metal ricochetting from the steel walls. The place was nothing less than a charnel house.

Then it was that the Sub knew why the admiral had sent him to investigate, for amongst the slain was Sir Noel's youngest son, a midshipman fresh from his two years' course on a training cruiser.

Putting his hand over his eyes as he vainly tried to shut out the mental vision of the annihilated gun's crew, Hamerton reeled away. Just as he gained the foot of the ladder to the conning tower a tremendous concussion, greater even than the impact of the huge shells, shook the ship. It seemed as if the twenty-five thousand tons of deadweight was lifted vertically for quite a foot.

The Sub exchanged glances with the lieutenant standing by the submerged steering wheel.

"Torpedoed," exclaimed the officer laconically. Up the fifty feet of vertical ladder Hamerton hastened. At the top he paused abruptly. The conning tower was filled with dense smoke. The admiral lay propped against the armoured walls with his forehead cut from temple to temple by a sliver of steel. The flag-lieutenant was down, slain by a fragment of the same shell that had killed his chief, while the captain, pale as a sheet, was supporting himself by the partly-shattered binnacle. Only the two petty officers remained unwounded, though completely dazed by the concussion.

"Glad you've come," said the captain weakly. "Pass the word for the commander. We must haul out of line. Tell him to take what steps he thinks——"

The captain's words trailed off into an unmeaning sentence, his head dropped on his chest, and he sank unconscious beside the body of the ill-fated admiral.

By the time the commander reached the conning tower the Royal Sovereign had automatically dropped out of station. A torpedo, fired by a badly shattered German warship, the Pommern, had struck her a few feet forward of the sternpost, shattering both rudders and the two starboard propellers. A few feet farther forward and nothing could have saved her from total destruction, for the powerful Schwartz-Kopff would have blown a hole large enough for a carriage to pass completely through her double skin. As it was, the after flats were completely flooded, and the flagship was deeply down by the stern.

At this juncture the engines were stopped, and screened from the enemy's fire by the Repulse, that gallantly intervened, the Royal Sovereign lost way when about two miles to the west of the first division of the British fleet.

Already the battle was decided. Superior numbers and gunnery won the day in spite of the frequent use of torpedoes by the Germans. Several of the British ships had, indeed, narrow escapes from these sinister and powerful weapons, for the range was an ideal one. Only the furious and accurate gunnery of the British ships and the speed of the two opposing fleets prevented the torpedoes from doing greater damage, for it was afterwards ascertained that in almost every case the concussion of the heavy shells destroyed all communication between the conning towers and the submerged torpedo-rooms of the various German ships.

Now, for the first time since the commencement of the action, Hamerton was able to see what was going on without. Thank God! All around were British and German ships flying the good old White Ensign—ships no longer, but merely battered and shattered masses of steel. Away in the haze firing was still being maintained in a desultory manner, but of the issue of the conflict there could be no doubt.

Suddenly an exclamation from a marine officer attracted Hamerton's attention. Following the direction of the officer's outstretched hand the Sub looked. At less than half a mile off lay the Orion. She was rolling sluggishly, owing to the immense weight and height above the waterline of her ten 13.5-inch guns. Although every unarmoured part of her above the side plating was either shot away or riddled, the rolling revealed the fact that below the waterline she was practically intact.

She was settling down on an even keel. The survivors of her crew were vainly attempting to check the inrush of water by means of collision mats, while those of her pumps which were still in a fit condition for use were engaged in throwing out large streams of water.

Then, even as Hamerton looked, the Orion ceased to recover herself. Her gigantic bulk turned slowly over to starboard till she capsized completely, and floated with her keel only a few feet above the water.

Those of her crew who were on deck were able for the most part to jump overboard. In some cases men ran up the side and gained a temporary refuge on the flat-sectioned bilges, while, seeing what had occurred, several destroyers hastened to the rescue.

Not a boat was to be found on any of the battleships and cruisers, save a few canvas collapsibles stowed under the armoured decks before the action began. Everything of a buoyant nature that was in danger of taking fire had either been left at the home dockyards or ruthlessly thrown overboard. In a modern battleship cleared for action there is no use for life-saving apparatus, however desirable it may be after the conflict is over.

Many of the swimmers of the Orion's crew were rescued by the destroyers, but before those clinging to the capsized battleship could be rescued, the compressed air within the hull burst through the comparatively thin steel plating with a roar like the explosion of a magazine. Amid a smother of foam the luckless vessel plunged to the bed of the North Sea.

This disaster was merely a repetition of the experiments made on the old Empress of India in 1913. In both cases the vessel was practically undamaged beneath the armoured deck, while the water was freely admitted above that particular deck. The result was that the stability of the vessel was completely disturbed, and the battleship capsized.

All around the sorely-stricken Royal Sovereign were equally badly-mauled vessels making temporary repairs. The captured German warships, numbering nine, had to be taken possession of by men swimming from the nearest British battleship. This done, Sir George Maynebrace, who had taken supreme command upon the death of Admiral Sir Noel Armitage, ordered those vessels that were no longer seaworthy to be destroyed, while the others were either taken in tow or proceeded under their own steam for the mouth of the Thames.

It was a matter of impossibility for the British admiral to follow up his advantage. So badly knocked about were the British battleships that they would be unable to attack the German fortified bases in the North Sea. All that could be done was to wait for the Mediterranean Fleet, mobilize the battleships in reserve, and join forces with the American squadron. Although the supremacy of the sea was decided, a hard task still remained ere the fierce and sanguinary struggle could be brought to an end.

CHAPTER XXV

The Fall of the Island Fortress

At a modest seven knots the battered Royal Sovereign wallowed in tow in the wake of the Barham. It seemed wonderful that she should have survived the ordeal, for in places the massive armour plates had been completely knocked away. Her bows were level with the water, while the whole of her quarter deck had been blown in by a bomb dropped from a German seaplane.

Almost the last shot fired at her by her principal antagonist, the gigantic Breslau, had hit the chase of one of the fifteen-inch guns in the second turret from the bows. The huge mass of metal had fractured, while the muzzle, falling upon the barbette next ahead and slightly below, had prevented both barbettes from being trained. Thus one shot had practically put four fifteen-inch guns out of action.

Wherever a heavy shell had struck against armour the latter had been made nearly red-hot, and for an hour or more after the fight it was almost impossible to place a hand on the heated metal.

The use of aerial craft above the fighting battleships was very limited during the action. Thanks to the preponderance of seaplanes, the British were able to keep the German aircraft well at a distance. The only noteworthy exception was the seaplane which contrived to drop a bomb on the Royal Sovereign's deck. She did not live to repeat the experiment, for a fragment of a German eleven-inch shell, ricochetting from the hood of the Royal Sovereign's after barbette, flew vertically upward for a height of nearly three hundred feet, literally cutting the daring seaplane in halves.

Nor did the submarines prove their vaunted merits. Detected from the British aircraft, these sinister vessels stood very little chance. Even had they come within striking distance it is doubtful whether they would not have damaged friend as well as foe, for in the disorder in the formation of the two fleets, and in the dense haze that enveloped them in less than a minute after the first broadside, it was a difficult matter to distinguish one ship from another.

Had the action taken place at night the submarine would doubtless have played an important part in deciding the battle.

Superiority in numbers of light-armoured cruisers and destroyers, combined with the coolness and precision of the men at the quick-firers, enabled the British to make short work of the German "mosquito fleet", although the former did not come out of the action without heavy loss. Nevertheless there was still the danger that some of the least-damaged German destroyers might again attempt a night attack upon the East Coast. Great were the rejoicings in Great Britain at the victory. They were not extravagant outbursts of joy, but heartfelt expressions of thankfulness that the great ordeal had been successfully passed. The imminent danger, made apparent by the damage done at South Shields, had taught a national lesson, while the great victory had been bought at a tremendous price in human lives—the sacrifice at the altar of maritime supremacy.

Directly the Royal Sovereign crept into the Nore she was ordered round to Portsmouth, since the dockyards of Chatham and Sheerness were quite unable to cope with the work of refitting any but the least-damaged ships. Towed by the Barham, and escorted by two destroyers, the crippled vessel reached Spithead, and was taken into harbour and docked without delay. The surviving officers and crew were at once turned over to the obsolescent battleship Collingwood, the flagship of the Eighth Battle Squadron.

Five days later the combined Anglo-American fleet left the Nore. Off the Texel the fleet was divided—the major portion to operate against Heligoland and the remainder to destroy, if possible, the defences of Borkum. All the United States' battleships were in the division detailed for the bombardment of Heligoland, since officers and men were actuated by the knowledge that an American citizen was still a prisoner in that island fortress.

It was a case of hasten slowly. The shallows around the mouths of the Elbe and Weser were admirably suited to the use of submarine mines, while every "gat" between the extensive sandbanks could be used by German torpedo craft. Local knowledge was a great factor in favour of the Teutonic torpedo craft.

It was with curious feelings that Hamerton looked once more upon the red, white, and green island of Heligoland. Only a short time back he was there a captive; now he was about to witness a demonstration of naval might and power against the heavily defended batteries that a diplomatic mistake on the part of Great Britain had raised into existence.

Admiral Maynebrace had done Hamerton the honour of asking his opinion, and, thanks to the Sub's knowledge, he was able to arrange his plans accordingly. The batteries on the south-western side of the island were to be left severely alone. Sandinsel was the key of the position. Once its guns were silenced the reduction of Heligoland would be a matter of course. Sir George, therefore, ordered the mine-creeping vessels—subsidized steam "drifters"—to advance under cover of the battle cruisers and clear away the mines to the north-east and south-east of Heligoland.

This was a hazardous duty, for the vessels engaged in the work were open to a torpedo attack from the destroyers either from the Heligoland base or from the mouths of the Elbe, Eider, Weser, and Jade. In the wake of the mine-creepers came the battleships, with torpedo nets out, so as to be prepared for an attack by the long-range Schwartz-Kopff locomotive torpedoes.

To add to the difficulties, the Germans had already removed all buoys and navigation marks, so that the ships had to be continuously making use of the lead line.

Directly night fell the battleships and battle cruisers steamed westwards with screened lights, so as to be safe from destroyer and submarine attack, leaving the British small craft to cope with any demonstration from the numerous German torpedo bases. Thus the nerve-racking ordeal of momentarily expecting an unseen blow was spared the already sorely taxed crews of the armoured fleet.

But what the battleships missed the destroyers had more than a full share of. Triple lines of these vessels patrolled the sea between the position where the Weser lightship was formerly stationed and that of the Rittergat light buoy. The destroyers on the flank kept their searchlights trained outwards in a horizontal position well abeam, while those in the centre line used their searchlights for the purpose of locating any hostile aircraft.

In spite of these precautions four of the British torpedo craft were sunk by German submarines without the former having a glimpse of their foes.

Before daybreak the battleships were back in their former stations, the American ships taking up a position to the north-east of Sandinsel, while the twenty-eight armoured British battleships directed their fire upon the Düne and East Kalbertan batteries of the same island. The destroyers were grouped into three divisions—the first to be attached to the United States ships in case of a hostile movement from North Haven; the second to lie three miles astern of the British battleships engaged in bombarding Sandinsel, so as to guard against a torpedo attack from South Haven; the third detailed to watch the mainland.

Exactly at eight in the morning the American flagship Wyoming opened the ball by planting a fifteen-inch shell fairly in the centre of the Krid Brunnen Battery. An enormous cloud of sand, smoke, and dust, mingled with heavier fragments, followed the explosion. It looked as if the magazine had been blown up, but a smart reply from the battery showed that this was not so.

The firing now became general, and the concentrated shells of the combined fleet literally' rained upon the Sandinsel forts. It seemed as if nothing could survive the terrible explosions of the heavy missiles, but with commendable pluck the German gunners stood to their task. Several of their shells struck the battleships, doing considerable damage, but the effect on board did not approach the carnage of the battle of the Galloper Sands. Nor was it to be wondered at, since the enemy had to spread their fire over a five-mile line of warships, while the latter were able to concentrate their guns upon a comparatively limited and immovable target.

In three hours from the time the Wyoming first opened fire the East Kalbertan, Krid Brunnen, and Düne batteries were silenced, and the British and American ships were able to direct their attention to the weaker West Kalbertan Battery and the torpedo flotillas sheltering between Heligoland and Sandinsel.

This they could do with comparative impunity, for with the exception of four fifteen-inch guns, mounted on the north-east side of Heligoland, the defensive armament consisted of lighter guns intended for use against torpedo craft.

The large guns were soon out of action. The hail of heavy shells knocked vast quantities of rock from the soft sandstone cliffs. In half an hour the damage was greater than the erosion of half a century. The emplacements, undermined by the fall of rock, were soon unmasked and rendered untenable.

But the German destroyers were not going to be sunk in harbour. Profiting by the haze of burnt cordite that enveloped the bombarding ships, thirty of these swift craft slipped out of South Haven. It was a forlorn hope, and nothing short of destruction awaited them, but before the end they meant to strike a heavy blow for the Fatherland.

Steaming at close on thirty-five knots, the devoted craft headed straight for the nearest British battleships—a distance of four miles from the south-east of Heligoland.

More than half the intervening space was covered before the threatened attack was noticed by the British flagship. A signal was instantly made for the light cruisers and destroyers in reserve to intercept the approaching hostile craft. Already it was too late. Only the light quick-firers of the British battleships could keep the enemy at bay.

In response to a general signal the huge warships turned eight points to starboard. That meant that instead of keeping broadside on to the forts they were steaming away from them. Hampered by their torpedo nets the manoeuvre was slowly executed, but each warship now presented a much smaller target to the German torpedoes, while there was more room between the battleships for the British destroyers to operate.

Temporarily the big-gun fire ceased. The sharp barks of the quick-firers resounded on all sides. Through the maelstrom of twelve-pounder shells the German destroyers tore. Several swung out of line, disabled and on the point of sinking; but the surviving vessels, admirably handled, avoided their stricken consorts and continued the headlong rush.

Then, acting smartly in response to a signal from the leading boat, the remaining destroyers ported helm sufficiently for the deck torpedo tubes to bear, and almost simultaneously thirty deadly Schwartz-Kopff weapons tore on their mission of destruction.

It was impossible for everyone to miss the mark. The sea was ruffled with the foam of the swiftly-travelling weapons. Some, exploding the nets, tore great rents in the meshes and unshipped or shattered the massive steel booms supporting the best anti-torpedo device that naval architects could devise. Others, following in their wake, struck home underneath the armoured plating of the battleships.

Explosion after explosion, outvieing the crack of the quick-firers, rose in the air. Huge vessels, mortally stricken, rolled sluggishly under the impact. Mingled with the din came the cheers of the exultant Germans. It was a modernized form of the old gladiatorial shout: "Hail, Caesar, those about to die salute thee"; for the cheers were those of doomed men.

Tearing betwixt the battleships came the British destroyers like wolves upon a sheepfold. This phase of action became a mêlée. In several cases the British craft, charging their opponents at full speed, literally cut these latter in twain. It was but another of those instances when, in the heat of battle, men neither ask nor expect quarter. Only four German boats, badly damaged, were able to regain a temporary and insecure shelter under the lee of Sandinsel.

Nevertheless they had struck a hard blow. The Bellerophon, hit thrice in quick succession, had sunk; the Ajax and Agamemnon were listing heavily, only their watertight bulkheads abaft the engine-rooms preventing them from going to the bottom. For offensive purposes they were now utterly useless. The Centurion and Formidable, having lost their rudders and propellers, had to be taken in tow, and sent, escorted by the battle cruisers Impregnable and Inflexible, to add to the congested state of the British dockyards.

Nothing daunted by these misfortunes the rest of the allied fleet maintained a hot fire. By five in the afternoon the east of the batteries of Sandinsel ceased to reply. The docks, factories and stores, and shipping on the east of Heligoland were either destroyed or in flames. The attack upon the island could now be pushed home.

Contrary to expectations the Zeppelins made no attempt to emerge from their place of concealment. It afterwards transpired that, more by accident than design, two heavy shells had simultaneously burst in the great artificial crater into which the airship sheds opened. The explosions were sufficient to wreck completely the three Zeppelins lying in the lofty caves.

As night fell the battleships made for the offing, while the British destroyers and light cruisers took the same precautions against attack as before.

At daybreak the bombardment was resumed. The Sandinsel batteries, having effected temporary repairs during the hours of darkness, reopened fire, but so feebly that in less than twenty minutes there was no reply to the British guns. The American warships, closing in from the north-east, directed their attention to the lighter batteries on the cliff side of Heligoland, and occasionally to shelling the barracks and searchlight station on the plateau. The British devoted their energies to the Sathurn battery and the southern portion of the island, sparing as far as possible the houses of the Unterland.

At ten minutes past nine a tremendous explosion shook the air. One of the Kentucky's shells had struck the principal magazine. The concussion and the fire that followed caused the vast oil reservoirs to ignite, and in a few moments the whole of the central portion of the rock seemed one mass of flames.

More feeble grew the reply of the German guns, and at noon the island fortress of Heligoland capitulated, without one shot being fired from the more powerful batteries on the south-western side, to which no vessel belonging to the allies had offered a chance for a single discharge.

As soon as the German flag was lowered from the captured island five hundred British and American marines were landed to take possession of the fire-swept rock that was but recently the pride of the Teutonic Empire.

Lieutenant Hamerton was one of the few naval officers to set foot ashore, but at his earnest request he was given permission to seek out his old comrade Detroit.

It was with feelings of elation that the young officer stood once more upon the stone jetty where but a few weeks previously he had been ignominiously escorted by a file of German marines. Now he was given a salute by a stalwart British marine who had been promptly posted at the head of the steps.

On his way to the Oberland—Hamerton had to walk, since the lift had been damaged during the bombardment—the Sub passed a party of German officers who were about to put off to the British flagship to satisfy the terms of the capitulation. One of them he recognized as Major Karl von Schloss.

Both men gravely saluted each other, then Hamerton advanced and held out his hand. The major took it without hesitation. He was one of many who, however bitter the defeat, took in the situation with becoming mien and grace. Hamerton bore him no ill feeling. True, Von Schloss had acted harshly to him when he was a prisoner, but the major really believed that the Sub was a British spy.

"He is safe," replied Von Schloss. "Before the firing commenced he was taken to the church, since we knew that would not be a mark for your guns."

"He is dead," replied Von Schloss, with evident emotion. "He fell during the bombardment."

Gravely Hamerton raised his right hand to the salute. His former enemy had given up his life on the altar of duty, a victim to his misguided efforts to further the interests of the Fatherland.

"There is no need," rejoined Major von Schloss. "General von Wittelsbach died as he wished, in the defence of a charge entrusted to him by the Kaiser. Believe me, he would never have survived the humiliation. But now, Herr Hamerton, I bid you farewell."

Both men shook hands and parted, the major hurrying after his companions, while the Sub wended his way towards the old church.

A number of armed German marines stood without the weatherbeaten fane. They were stationed there to guard various prisoners who had been hastily removed from the barrack prison at the commencement of the attack.

But before Hamerton could approach and make known the nature of his mission a well-known voice hailed him from one of the narrow windows of the tower.

"Hallo, old man! So they've let you out? Guess it's about time I thought about moving. I guess you weren't long in getting into uniform."

"Considering I haven't taken off my things for the last three days I cannot agree with you," replied the Sub, with a hearty laugh. "I've come to bring you out of this, Detroit, so the sooner you come down from your perch the better."

"I reckon I've had a rotten time," remarked Detroit, as the two friends made their way to the shore. "But it's worth it," he added enthusiastically. "To look out of that window and to see the Yankee eagle and the British lion knocking spots off the German was the finest sight in creation."

Hamerton shrugged his shoulders. He was thinking of the carnage that had been wrought on both sides ere "the finest sight in creation" was completed.

"Yes," he said slowly, "I suppose it was. The onlookers always see the best of the game."

That same day the articles of capitulation were drawn up and signed. The officers and some of the garrison of Heligoland, upon giving their parole, were permitted to withdraw with their private effects. The guns were either burst by means of guncotton or toppled over the cliffs, the defensive works that had escaped serious damage during the bombardment were blown up, and the captured war vessels either sunk or sent across the North Sea.

Twenty-four hours later an armistice was declared between the Anglo-American allies and Germany. The humiliation of the German Empire as a naval power was complete.

Peace was definitely declared in less than a fortnight from the unprovoked but abortive raid upon the east coast of Great Britain. By the terms of the treaty Germany was bound down not to maintain a fleet of more than twenty small cruisers. A comparatively small indemnity was demanded, while the fortifications of Borkum were ordered to be razed.

Heligoland was by mutual consent restored to its former masters, the Danes, and once and for all the menace to Great Britain ceased to exist.

The war, terrible while it lasted, brought good in its train. The exhausting struggle for naval supremacy ceased. It was universally conceded that the great English-speaking nations should rule the sea, and almost automatically the Great Powers were able to cut down their almost overwhelming expenses in naval armaments.

The victors had not been ungenerous or vindictive; they had laid no violent restriction upon their former enemy. Germany could, and did, still expand her overseas trade without let or hindrance. The settlement of sea supremacy meant a new era of peace and prosperity.

After the termination of the war, Hamerton, now promoted to the rank of lieutenant, obtained a shore appointment in Portsmouth Dockyard. Every summer the ketch Diomeda puts in an appearance in the Solent, and Hamerton, Detroit, Octavius Smith, and Stirling generally made a point of having a month's cruise together in the stanch little craft.

Often, on some quiet evening, the Diomeda will be found snugly moored in some sheltered and secluded creek of the Solent, while down below in her cosy cabin the four men will be exchanging reminiscences and recalling the events that led to the capture of the sea-girt fortress of Heligoland.

Transcriber's Notes:

This book contains a number of misprints.
The following misprints have been corrected:

[Any misculation] —> [Any miscalculation]
[dull-back] —> [dull-black]
[degree of enthusiam] —> [degree of enthusiasm]
[overunning] —> [overrunning]
[Barracading] —> [Barricading]
[befel] —> [befell]
[to give an explanaation] —> [to give an explanation]

A few cases of punctuation errors were corrected, but are not mentioned here.

CHAP.
I.	Man Overboard
II.	Through the Fog
III.	A Loss and a Find
IV.	Arrested
V.	A Discovery
VI.	Von Wittelsbach's Plan
VII.	Official Hindrances
VIII.	Sentenced
IX.	On the Scent
X.	In the Prison Cell
XI.	A Night of Toil
XII.	Investigations
XIII.	An Experiment with a Zeppelin
XIV.	The Second Night of Liberty
XV.	Recaptured
XVI.	The News Leaks Out
XVII.	The Sandinsel Tunnel
XVIII.	The Errant Airship
XIX.	At the Mercy of the Winds
XX.	Homeward Bound
XXI.	Good Old Hamerton!
XXII.	A Momentous Decision
XXIII.	First Blood
XXIV.	The Battle of the Galloper Sands
XXV.	The Fall of the Island Fortress

By PERCY F. WESTERMAN


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